1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2020 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "displaced-stepping.h"
23 #include "gdbsupport/common-defs.h"
24 #include "gdbsupport/common-utils.h"
30 #include "breakpoint.h"
34 #include "target-connection.h"
35 #include "gdbthread.h"
43 #include "observable.h"
48 #include "mi/mi-common.h"
49 #include "event-top.h"
51 #include "record-full.h"
52 #include "inline-frame.h"
54 #include "tracepoint.h"
58 #include "completer.h"
59 #include "target-descriptions.h"
60 #include "target-dcache.h"
63 #include "gdbsupport/event-loop.h"
64 #include "thread-fsm.h"
65 #include "gdbsupport/enum-flags.h"
66 #include "progspace-and-thread.h"
67 #include "gdbsupport/gdb_optional.h"
68 #include "arch-utils.h"
69 #include "gdbsupport/scope-exit.h"
70 #include "gdbsupport/forward-scope-exit.h"
71 #include "gdbsupport/gdb_select.h"
72 #include <unordered_map>
73 #include "async-event.h"
75 /* Prototypes for local functions */
77 static void sig_print_info (enum gdb_signal
);
79 static void sig_print_header (void);
81 static void follow_inferior_reset_breakpoints (void);
83 static int currently_stepping (struct thread_info
*tp
);
85 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
87 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
89 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
91 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
93 static void resume (gdb_signal sig
);
95 static void wait_for_inferior (inferior
*inf
);
97 /* Asynchronous signal handler registered as event loop source for
98 when we have pending events ready to be passed to the core. */
99 static struct async_event_handler
*infrun_async_inferior_event_token
;
101 /* Stores whether infrun_async was previously enabled or disabled.
102 Starts off as -1, indicating "never enabled/disabled". */
103 static int infrun_is_async
= -1;
105 #define infrun_log_debug(fmt, args...) \
106 infrun_log_debug_1 (__LINE__, __func__, fmt, ##args)
108 static void ATTRIBUTE_PRINTF(3, 4)
109 infrun_log_debug_1 (int line
, const char *func
,
110 const char *fmt
, ...)
115 va_start (args
, fmt
);
116 std::string msg
= string_vprintf (fmt
, args
);
119 fprintf_unfiltered (gdb_stdout
, "infrun: %s: %s\n", func
, msg
.c_str ());
126 infrun_async (int enable
)
128 if (infrun_is_async
!= enable
)
130 infrun_is_async
= enable
;
132 infrun_log_debug ("enable=%d", enable
);
135 mark_async_event_handler (infrun_async_inferior_event_token
);
137 clear_async_event_handler (infrun_async_inferior_event_token
);
144 mark_infrun_async_event_handler (void)
146 mark_async_event_handler (infrun_async_inferior_event_token
);
149 /* When set, stop the 'step' command if we enter a function which has
150 no line number information. The normal behavior is that we step
151 over such function. */
152 bool step_stop_if_no_debug
= false;
154 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
155 struct cmd_list_element
*c
, const char *value
)
157 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
160 /* proceed and normal_stop use this to notify the user when the
161 inferior stopped in a different thread than it had been running
164 static ptid_t previous_inferior_ptid
;
166 /* If set (default for legacy reasons), when following a fork, GDB
167 will detach from one of the fork branches, child or parent.
168 Exactly which branch is detached depends on 'set follow-fork-mode'
171 static bool detach_fork
= true;
173 bool debug_displaced
= false;
175 show_debug_displaced (struct ui_file
*file
, int from_tty
,
176 struct cmd_list_element
*c
, const char *value
)
178 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
181 unsigned int debug_infrun
= 0;
183 show_debug_infrun (struct ui_file
*file
, int from_tty
,
184 struct cmd_list_element
*c
, const char *value
)
186 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
190 /* Support for disabling address space randomization. */
192 bool disable_randomization
= true;
195 show_disable_randomization (struct ui_file
*file
, int from_tty
,
196 struct cmd_list_element
*c
, const char *value
)
198 if (target_supports_disable_randomization ())
199 fprintf_filtered (file
,
200 _("Disabling randomization of debuggee's "
201 "virtual address space is %s.\n"),
204 fputs_filtered (_("Disabling randomization of debuggee's "
205 "virtual address space is unsupported on\n"
206 "this platform.\n"), file
);
210 set_disable_randomization (const char *args
, int from_tty
,
211 struct cmd_list_element
*c
)
213 if (!target_supports_disable_randomization ())
214 error (_("Disabling randomization of debuggee's "
215 "virtual address space is unsupported on\n"
219 /* User interface for non-stop mode. */
221 bool non_stop
= false;
222 static bool non_stop_1
= false;
225 set_non_stop (const char *args
, int from_tty
,
226 struct cmd_list_element
*c
)
228 if (target_has_execution
)
230 non_stop_1
= non_stop
;
231 error (_("Cannot change this setting while the inferior is running."));
234 non_stop
= non_stop_1
;
238 show_non_stop (struct ui_file
*file
, int from_tty
,
239 struct cmd_list_element
*c
, const char *value
)
241 fprintf_filtered (file
,
242 _("Controlling the inferior in non-stop mode is %s.\n"),
246 /* "Observer mode" is somewhat like a more extreme version of
247 non-stop, in which all GDB operations that might affect the
248 target's execution have been disabled. */
250 bool observer_mode
= false;
251 static bool observer_mode_1
= false;
254 set_observer_mode (const char *args
, int from_tty
,
255 struct cmd_list_element
*c
)
257 if (target_has_execution
)
259 observer_mode_1
= observer_mode
;
260 error (_("Cannot change this setting while the inferior is running."));
263 observer_mode
= observer_mode_1
;
265 may_write_registers
= !observer_mode
;
266 may_write_memory
= !observer_mode
;
267 may_insert_breakpoints
= !observer_mode
;
268 may_insert_tracepoints
= !observer_mode
;
269 /* We can insert fast tracepoints in or out of observer mode,
270 but enable them if we're going into this mode. */
272 may_insert_fast_tracepoints
= true;
273 may_stop
= !observer_mode
;
274 update_target_permissions ();
276 /* Going *into* observer mode we must force non-stop, then
277 going out we leave it that way. */
280 pagination_enabled
= 0;
281 non_stop
= non_stop_1
= true;
285 printf_filtered (_("Observer mode is now %s.\n"),
286 (observer_mode
? "on" : "off"));
290 show_observer_mode (struct ui_file
*file
, int from_tty
,
291 struct cmd_list_element
*c
, const char *value
)
293 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
296 /* This updates the value of observer mode based on changes in
297 permissions. Note that we are deliberately ignoring the values of
298 may-write-registers and may-write-memory, since the user may have
299 reason to enable these during a session, for instance to turn on a
300 debugging-related global. */
303 update_observer_mode (void)
305 bool newval
= (!may_insert_breakpoints
306 && !may_insert_tracepoints
307 && may_insert_fast_tracepoints
311 /* Let the user know if things change. */
312 if (newval
!= observer_mode
)
313 printf_filtered (_("Observer mode is now %s.\n"),
314 (newval
? "on" : "off"));
316 observer_mode
= observer_mode_1
= newval
;
319 /* Tables of how to react to signals; the user sets them. */
321 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
322 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
323 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
325 /* Table of signals that are registered with "catch signal". A
326 non-zero entry indicates that the signal is caught by some "catch
328 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
330 /* Table of signals that the target may silently handle.
331 This is automatically determined from the flags above,
332 and simply cached here. */
333 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
335 #define SET_SIGS(nsigs,sigs,flags) \
337 int signum = (nsigs); \
338 while (signum-- > 0) \
339 if ((sigs)[signum]) \
340 (flags)[signum] = 1; \
343 #define UNSET_SIGS(nsigs,sigs,flags) \
345 int signum = (nsigs); \
346 while (signum-- > 0) \
347 if ((sigs)[signum]) \
348 (flags)[signum] = 0; \
351 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
352 this function is to avoid exporting `signal_program'. */
355 update_signals_program_target (void)
357 target_program_signals (signal_program
);
360 /* Value to pass to target_resume() to cause all threads to resume. */
362 #define RESUME_ALL minus_one_ptid
364 /* Command list pointer for the "stop" placeholder. */
366 static struct cmd_list_element
*stop_command
;
368 /* Nonzero if we want to give control to the user when we're notified
369 of shared library events by the dynamic linker. */
370 int stop_on_solib_events
;
372 /* Enable or disable optional shared library event breakpoints
373 as appropriate when the above flag is changed. */
376 set_stop_on_solib_events (const char *args
,
377 int from_tty
, struct cmd_list_element
*c
)
379 update_solib_breakpoints ();
383 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
384 struct cmd_list_element
*c
, const char *value
)
386 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
390 /* Nonzero after stop if current stack frame should be printed. */
392 static int stop_print_frame
;
394 /* This is a cached copy of the target/ptid/waitstatus of the last
395 event returned by target_wait()/deprecated_target_wait_hook().
396 This information is returned by get_last_target_status(). */
397 static process_stratum_target
*target_last_proc_target
;
398 static ptid_t target_last_wait_ptid
;
399 static struct target_waitstatus target_last_waitstatus
;
401 void init_thread_stepping_state (struct thread_info
*tss
);
403 static const char follow_fork_mode_child
[] = "child";
404 static const char follow_fork_mode_parent
[] = "parent";
406 static const char *const follow_fork_mode_kind_names
[] = {
407 follow_fork_mode_child
,
408 follow_fork_mode_parent
,
412 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
414 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
415 struct cmd_list_element
*c
, const char *value
)
417 fprintf_filtered (file
,
418 _("Debugger response to a program "
419 "call of fork or vfork is \"%s\".\n"),
424 /* Handle changes to the inferior list based on the type of fork,
425 which process is being followed, and whether the other process
426 should be detached. On entry inferior_ptid must be the ptid of
427 the fork parent. At return inferior_ptid is the ptid of the
428 followed inferior. */
431 follow_fork_inferior (bool follow_child
, bool detach_fork
)
434 ptid_t parent_ptid
, child_ptid
;
436 has_vforked
= (inferior_thread ()->pending_follow
.kind
437 == TARGET_WAITKIND_VFORKED
);
438 parent_ptid
= inferior_ptid
;
439 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
442 && !non_stop
/* Non-stop always resumes both branches. */
443 && current_ui
->prompt_state
== PROMPT_BLOCKED
444 && !(follow_child
|| detach_fork
|| sched_multi
))
446 /* The parent stays blocked inside the vfork syscall until the
447 child execs or exits. If we don't let the child run, then
448 the parent stays blocked. If we're telling the parent to run
449 in the foreground, the user will not be able to ctrl-c to get
450 back the terminal, effectively hanging the debug session. */
451 fprintf_filtered (gdb_stderr
, _("\
452 Can not resume the parent process over vfork in the foreground while\n\
453 holding the child stopped. Try \"set detach-on-fork\" or \
454 \"set schedule-multiple\".\n"));
460 /* Detach new forked process? */
463 /* Before detaching from the child, remove all breakpoints
464 from it. If we forked, then this has already been taken
465 care of by infrun.c. If we vforked however, any
466 breakpoint inserted in the parent is visible in the
467 child, even those added while stopped in a vfork
468 catchpoint. This will remove the breakpoints from the
469 parent also, but they'll be reinserted below. */
472 /* Keep breakpoints list in sync. */
473 remove_breakpoints_inf (current_inferior ());
476 if (print_inferior_events
)
478 /* Ensure that we have a process ptid. */
479 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
481 target_terminal::ours_for_output ();
482 fprintf_filtered (gdb_stdlog
,
483 _("[Detaching after %s from child %s]\n"),
484 has_vforked
? "vfork" : "fork",
485 target_pid_to_str (process_ptid
).c_str ());
490 struct inferior
*parent_inf
, *child_inf
;
492 /* Add process to GDB's tables. */
493 child_inf
= add_inferior (child_ptid
.pid ());
495 parent_inf
= current_inferior ();
496 child_inf
->attach_flag
= parent_inf
->attach_flag
;
497 copy_terminal_info (child_inf
, parent_inf
);
498 child_inf
->gdbarch
= parent_inf
->gdbarch
;
499 copy_inferior_target_desc_info (child_inf
, parent_inf
);
501 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
503 set_current_inferior (child_inf
);
504 switch_to_no_thread ();
505 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
506 push_target (parent_inf
->process_target ());
507 add_thread_silent (child_inf
->process_target (), child_ptid
);
508 inferior_ptid
= child_ptid
;
510 /* If this is a vfork child, then the address-space is
511 shared with the parent. */
514 child_inf
->pspace
= parent_inf
->pspace
;
515 child_inf
->aspace
= parent_inf
->aspace
;
519 /* The parent will be frozen until the child is done
520 with the shared region. Keep track of the
522 child_inf
->vfork_parent
= parent_inf
;
523 child_inf
->pending_detach
= 0;
524 parent_inf
->vfork_child
= child_inf
;
525 parent_inf
->pending_detach
= 0;
529 child_inf
->aspace
= new_address_space ();
530 child_inf
->pspace
= new program_space (child_inf
->aspace
);
531 child_inf
->removable
= 1;
532 set_current_program_space (child_inf
->pspace
);
533 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
535 /* Let the shared library layer (e.g., solib-svr4) learn
536 about this new process, relocate the cloned exec, pull
537 in shared libraries, and install the solib event
538 breakpoint. If a "cloned-VM" event was propagated
539 better throughout the core, this wouldn't be
541 solib_create_inferior_hook (0);
547 struct inferior
*parent_inf
;
549 parent_inf
= current_inferior ();
551 /* If we detached from the child, then we have to be careful
552 to not insert breakpoints in the parent until the child
553 is done with the shared memory region. However, if we're
554 staying attached to the child, then we can and should
555 insert breakpoints, so that we can debug it. A
556 subsequent child exec or exit is enough to know when does
557 the child stops using the parent's address space. */
558 parent_inf
->waiting_for_vfork_done
= detach_fork
;
559 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
564 /* Follow the child. */
565 struct inferior
*parent_inf
, *child_inf
;
566 struct program_space
*parent_pspace
;
568 if (print_inferior_events
)
570 std::string parent_pid
= target_pid_to_str (parent_ptid
);
571 std::string child_pid
= target_pid_to_str (child_ptid
);
573 target_terminal::ours_for_output ();
574 fprintf_filtered (gdb_stdlog
,
575 _("[Attaching after %s %s to child %s]\n"),
577 has_vforked
? "vfork" : "fork",
581 /* Add the new inferior first, so that the target_detach below
582 doesn't unpush the target. */
584 child_inf
= add_inferior (child_ptid
.pid ());
586 parent_inf
= current_inferior ();
587 child_inf
->attach_flag
= parent_inf
->attach_flag
;
588 copy_terminal_info (child_inf
, parent_inf
);
589 child_inf
->gdbarch
= parent_inf
->gdbarch
;
590 copy_inferior_target_desc_info (child_inf
, parent_inf
);
592 parent_pspace
= parent_inf
->pspace
;
594 process_stratum_target
*target
= parent_inf
->process_target ();
597 /* Hold a strong reference to the target while (maybe)
598 detaching the parent. Otherwise detaching could close the
600 auto target_ref
= target_ops_ref::new_reference (target
);
602 /* If we're vforking, we want to hold on to the parent until
603 the child exits or execs. At child exec or exit time we
604 can remove the old breakpoints from the parent and detach
605 or resume debugging it. Otherwise, detach the parent now;
606 we'll want to reuse it's program/address spaces, but we
607 can't set them to the child before removing breakpoints
608 from the parent, otherwise, the breakpoints module could
609 decide to remove breakpoints from the wrong process (since
610 they'd be assigned to the same address space). */
614 gdb_assert (child_inf
->vfork_parent
== NULL
);
615 gdb_assert (parent_inf
->vfork_child
== NULL
);
616 child_inf
->vfork_parent
= parent_inf
;
617 child_inf
->pending_detach
= 0;
618 parent_inf
->vfork_child
= child_inf
;
619 parent_inf
->pending_detach
= detach_fork
;
620 parent_inf
->waiting_for_vfork_done
= 0;
622 else if (detach_fork
)
624 if (print_inferior_events
)
626 /* Ensure that we have a process ptid. */
627 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
629 target_terminal::ours_for_output ();
630 fprintf_filtered (gdb_stdlog
,
631 _("[Detaching after fork from "
633 target_pid_to_str (process_ptid
).c_str ());
636 target_detach (parent_inf
, 0);
640 /* Note that the detach above makes PARENT_INF dangling. */
642 /* Add the child thread to the appropriate lists, and switch
643 to this new thread, before cloning the program space, and
644 informing the solib layer about this new process. */
646 set_current_inferior (child_inf
);
647 push_target (target
);
650 add_thread_silent (target
, child_ptid
);
651 inferior_ptid
= child_ptid
;
653 /* If this is a vfork child, then the address-space is shared
654 with the parent. If we detached from the parent, then we can
655 reuse the parent's program/address spaces. */
656 if (has_vforked
|| detach_fork
)
658 child_inf
->pspace
= parent_pspace
;
659 child_inf
->aspace
= child_inf
->pspace
->aspace
;
665 child_inf
->aspace
= new_address_space ();
666 child_inf
->pspace
= new program_space (child_inf
->aspace
);
667 child_inf
->removable
= 1;
668 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
669 set_current_program_space (child_inf
->pspace
);
670 clone_program_space (child_inf
->pspace
, parent_pspace
);
672 /* Let the shared library layer (e.g., solib-svr4) learn
673 about this new process, relocate the cloned exec, pull in
674 shared libraries, and install the solib event breakpoint.
675 If a "cloned-VM" event was propagated better throughout
676 the core, this wouldn't be required. */
677 solib_create_inferior_hook (0);
681 return target_follow_fork (follow_child
, detach_fork
);
684 /* Tell the target to follow the fork we're stopped at. Returns true
685 if the inferior should be resumed; false, if the target for some
686 reason decided it's best not to resume. */
691 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
692 bool should_resume
= true;
693 struct thread_info
*tp
;
695 /* Copy user stepping state to the new inferior thread. FIXME: the
696 followed fork child thread should have a copy of most of the
697 parent thread structure's run control related fields, not just these.
698 Initialized to avoid "may be used uninitialized" warnings from gcc. */
699 struct breakpoint
*step_resume_breakpoint
= NULL
;
700 struct breakpoint
*exception_resume_breakpoint
= NULL
;
701 CORE_ADDR step_range_start
= 0;
702 CORE_ADDR step_range_end
= 0;
703 int current_line
= 0;
704 symtab
*current_symtab
= NULL
;
705 struct frame_id step_frame_id
= { 0 };
706 struct thread_fsm
*thread_fsm
= NULL
;
710 process_stratum_target
*wait_target
;
712 struct target_waitstatus wait_status
;
714 /* Get the last target status returned by target_wait(). */
715 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
717 /* If not stopped at a fork event, then there's nothing else to
719 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
720 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
723 /* Check if we switched over from WAIT_PTID, since the event was
725 if (wait_ptid
!= minus_one_ptid
726 && (current_inferior ()->process_target () != wait_target
727 || inferior_ptid
!= wait_ptid
))
729 /* We did. Switch back to WAIT_PTID thread, to tell the
730 target to follow it (in either direction). We'll
731 afterwards refuse to resume, and inform the user what
733 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
734 switch_to_thread (wait_thread
);
735 should_resume
= false;
739 tp
= inferior_thread ();
741 /* If there were any forks/vforks that were caught and are now to be
742 followed, then do so now. */
743 switch (tp
->pending_follow
.kind
)
745 case TARGET_WAITKIND_FORKED
:
746 case TARGET_WAITKIND_VFORKED
:
748 ptid_t parent
, child
;
750 /* If the user did a next/step, etc, over a fork call,
751 preserve the stepping state in the fork child. */
752 if (follow_child
&& should_resume
)
754 step_resume_breakpoint
= clone_momentary_breakpoint
755 (tp
->control
.step_resume_breakpoint
);
756 step_range_start
= tp
->control
.step_range_start
;
757 step_range_end
= tp
->control
.step_range_end
;
758 current_line
= tp
->current_line
;
759 current_symtab
= tp
->current_symtab
;
760 step_frame_id
= tp
->control
.step_frame_id
;
761 exception_resume_breakpoint
762 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
763 thread_fsm
= tp
->thread_fsm
;
765 /* For now, delete the parent's sr breakpoint, otherwise,
766 parent/child sr breakpoints are considered duplicates,
767 and the child version will not be installed. Remove
768 this when the breakpoints module becomes aware of
769 inferiors and address spaces. */
770 delete_step_resume_breakpoint (tp
);
771 tp
->control
.step_range_start
= 0;
772 tp
->control
.step_range_end
= 0;
773 tp
->control
.step_frame_id
= null_frame_id
;
774 delete_exception_resume_breakpoint (tp
);
775 tp
->thread_fsm
= NULL
;
778 parent
= inferior_ptid
;
779 child
= tp
->pending_follow
.value
.related_pid
;
781 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
782 /* Set up inferior(s) as specified by the caller, and tell the
783 target to do whatever is necessary to follow either parent
785 if (follow_fork_inferior (follow_child
, detach_fork
))
787 /* Target refused to follow, or there's some other reason
788 we shouldn't resume. */
793 /* This pending follow fork event is now handled, one way
794 or another. The previous selected thread may be gone
795 from the lists by now, but if it is still around, need
796 to clear the pending follow request. */
797 tp
= find_thread_ptid (parent_targ
, parent
);
799 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
801 /* This makes sure we don't try to apply the "Switched
802 over from WAIT_PID" logic above. */
803 nullify_last_target_wait_ptid ();
805 /* If we followed the child, switch to it... */
808 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
809 switch_to_thread (child_thr
);
811 /* ... and preserve the stepping state, in case the
812 user was stepping over the fork call. */
815 tp
= inferior_thread ();
816 tp
->control
.step_resume_breakpoint
817 = step_resume_breakpoint
;
818 tp
->control
.step_range_start
= step_range_start
;
819 tp
->control
.step_range_end
= step_range_end
;
820 tp
->current_line
= current_line
;
821 tp
->current_symtab
= current_symtab
;
822 tp
->control
.step_frame_id
= step_frame_id
;
823 tp
->control
.exception_resume_breakpoint
824 = exception_resume_breakpoint
;
825 tp
->thread_fsm
= thread_fsm
;
829 /* If we get here, it was because we're trying to
830 resume from a fork catchpoint, but, the user
831 has switched threads away from the thread that
832 forked. In that case, the resume command
833 issued is most likely not applicable to the
834 child, so just warn, and refuse to resume. */
835 warning (_("Not resuming: switched threads "
836 "before following fork child."));
839 /* Reset breakpoints in the child as appropriate. */
840 follow_inferior_reset_breakpoints ();
845 case TARGET_WAITKIND_SPURIOUS
:
846 /* Nothing to follow. */
849 internal_error (__FILE__
, __LINE__
,
850 "Unexpected pending_follow.kind %d\n",
851 tp
->pending_follow
.kind
);
855 return should_resume
;
859 follow_inferior_reset_breakpoints (void)
861 struct thread_info
*tp
= inferior_thread ();
863 /* Was there a step_resume breakpoint? (There was if the user
864 did a "next" at the fork() call.) If so, explicitly reset its
865 thread number. Cloned step_resume breakpoints are disabled on
866 creation, so enable it here now that it is associated with the
869 step_resumes are a form of bp that are made to be per-thread.
870 Since we created the step_resume bp when the parent process
871 was being debugged, and now are switching to the child process,
872 from the breakpoint package's viewpoint, that's a switch of
873 "threads". We must update the bp's notion of which thread
874 it is for, or it'll be ignored when it triggers. */
876 if (tp
->control
.step_resume_breakpoint
)
878 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
879 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
882 /* Treat exception_resume breakpoints like step_resume breakpoints. */
883 if (tp
->control
.exception_resume_breakpoint
)
885 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
886 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
889 /* Reinsert all breakpoints in the child. The user may have set
890 breakpoints after catching the fork, in which case those
891 were never set in the child, but only in the parent. This makes
892 sure the inserted breakpoints match the breakpoint list. */
894 breakpoint_re_set ();
895 insert_breakpoints ();
898 /* The child has exited or execed: resume threads of the parent the
899 user wanted to be executing. */
902 proceed_after_vfork_done (struct thread_info
*thread
,
905 int pid
= * (int *) arg
;
907 if (thread
->ptid
.pid () == pid
908 && thread
->state
== THREAD_RUNNING
909 && !thread
->executing
910 && !thread
->stop_requested
911 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
913 infrun_log_debug ("resuming vfork parent thread %s",
914 target_pid_to_str (thread
->ptid
).c_str ());
916 switch_to_thread (thread
);
917 clear_proceed_status (0);
918 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
924 /* Save/restore inferior_ptid, current program space and current
925 inferior. Only use this if the current context points at an exited
926 inferior (and therefore there's no current thread to save). */
927 class scoped_restore_exited_inferior
930 scoped_restore_exited_inferior ()
931 : m_saved_ptid (&inferior_ptid
)
935 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
936 scoped_restore_current_program_space m_pspace
;
937 scoped_restore_current_inferior m_inferior
;
940 /* Called whenever we notice an exec or exit event, to handle
941 detaching or resuming a vfork parent. */
944 handle_vfork_child_exec_or_exit (int exec
)
946 struct inferior
*inf
= current_inferior ();
948 if (inf
->vfork_parent
)
950 int resume_parent
= -1;
952 /* This exec or exit marks the end of the shared memory region
953 between the parent and the child. Break the bonds. */
954 inferior
*vfork_parent
= inf
->vfork_parent
;
955 inf
->vfork_parent
->vfork_child
= NULL
;
956 inf
->vfork_parent
= NULL
;
958 /* If the user wanted to detach from the parent, now is the
960 if (vfork_parent
->pending_detach
)
962 struct thread_info
*tp
;
963 struct program_space
*pspace
;
964 struct address_space
*aspace
;
966 /* follow-fork child, detach-on-fork on. */
968 vfork_parent
->pending_detach
= 0;
970 gdb::optional
<scoped_restore_exited_inferior
>
971 maybe_restore_inferior
;
972 gdb::optional
<scoped_restore_current_pspace_and_thread
>
973 maybe_restore_thread
;
975 /* If we're handling a child exit, then inferior_ptid points
976 at the inferior's pid, not to a thread. */
978 maybe_restore_inferior
.emplace ();
980 maybe_restore_thread
.emplace ();
982 /* We're letting loose of the parent. */
983 tp
= any_live_thread_of_inferior (vfork_parent
);
984 switch_to_thread (tp
);
986 /* We're about to detach from the parent, which implicitly
987 removes breakpoints from its address space. There's a
988 catch here: we want to reuse the spaces for the child,
989 but, parent/child are still sharing the pspace at this
990 point, although the exec in reality makes the kernel give
991 the child a fresh set of new pages. The problem here is
992 that the breakpoints module being unaware of this, would
993 likely chose the child process to write to the parent
994 address space. Swapping the child temporarily away from
995 the spaces has the desired effect. Yes, this is "sort
998 pspace
= inf
->pspace
;
999 aspace
= inf
->aspace
;
1003 if (print_inferior_events
)
1006 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
1008 target_terminal::ours_for_output ();
1012 fprintf_filtered (gdb_stdlog
,
1013 _("[Detaching vfork parent %s "
1014 "after child exec]\n"), pidstr
.c_str ());
1018 fprintf_filtered (gdb_stdlog
,
1019 _("[Detaching vfork parent %s "
1020 "after child exit]\n"), pidstr
.c_str ());
1024 target_detach (vfork_parent
, 0);
1027 inf
->pspace
= pspace
;
1028 inf
->aspace
= aspace
;
1032 /* We're staying attached to the parent, so, really give the
1033 child a new address space. */
1034 inf
->pspace
= new program_space (maybe_new_address_space ());
1035 inf
->aspace
= inf
->pspace
->aspace
;
1037 set_current_program_space (inf
->pspace
);
1039 resume_parent
= vfork_parent
->pid
;
1043 /* If this is a vfork child exiting, then the pspace and
1044 aspaces were shared with the parent. Since we're
1045 reporting the process exit, we'll be mourning all that is
1046 found in the address space, and switching to null_ptid,
1047 preparing to start a new inferior. But, since we don't
1048 want to clobber the parent's address/program spaces, we
1049 go ahead and create a new one for this exiting
1052 /* Switch to null_ptid while running clone_program_space, so
1053 that clone_program_space doesn't want to read the
1054 selected frame of a dead process. */
1055 scoped_restore restore_ptid
1056 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1058 inf
->pspace
= new program_space (maybe_new_address_space ());
1059 inf
->aspace
= inf
->pspace
->aspace
;
1060 set_current_program_space (inf
->pspace
);
1062 inf
->symfile_flags
= SYMFILE_NO_READ
;
1063 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1065 resume_parent
= vfork_parent
->pid
;
1068 gdb_assert (current_program_space
== inf
->pspace
);
1070 if (non_stop
&& resume_parent
!= -1)
1072 /* If the user wanted the parent to be running, let it go
1074 scoped_restore_current_thread restore_thread
;
1076 infrun_log_debug ("resuming vfork parent process %d",
1079 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1084 /* Enum strings for "set|show follow-exec-mode". */
1086 static const char follow_exec_mode_new
[] = "new";
1087 static const char follow_exec_mode_same
[] = "same";
1088 static const char *const follow_exec_mode_names
[] =
1090 follow_exec_mode_new
,
1091 follow_exec_mode_same
,
1095 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1097 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1098 struct cmd_list_element
*c
, const char *value
)
1100 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1103 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1106 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1108 struct inferior
*inf
= current_inferior ();
1109 int pid
= ptid
.pid ();
1110 ptid_t process_ptid
;
1112 /* Switch terminal for any messages produced e.g. by
1113 breakpoint_re_set. */
1114 target_terminal::ours_for_output ();
1116 /* This is an exec event that we actually wish to pay attention to.
1117 Refresh our symbol table to the newly exec'd program, remove any
1118 momentary bp's, etc.
1120 If there are breakpoints, they aren't really inserted now,
1121 since the exec() transformed our inferior into a fresh set
1124 We want to preserve symbolic breakpoints on the list, since
1125 we have hopes that they can be reset after the new a.out's
1126 symbol table is read.
1128 However, any "raw" breakpoints must be removed from the list
1129 (e.g., the solib bp's), since their address is probably invalid
1132 And, we DON'T want to call delete_breakpoints() here, since
1133 that may write the bp's "shadow contents" (the instruction
1134 value that was overwritten with a TRAP instruction). Since
1135 we now have a new a.out, those shadow contents aren't valid. */
1137 mark_breakpoints_out ();
1139 /* The target reports the exec event to the main thread, even if
1140 some other thread does the exec, and even if the main thread was
1141 stopped or already gone. We may still have non-leader threads of
1142 the process on our list. E.g., on targets that don't have thread
1143 exit events (like remote); or on native Linux in non-stop mode if
1144 there were only two threads in the inferior and the non-leader
1145 one is the one that execs (and nothing forces an update of the
1146 thread list up to here). When debugging remotely, it's best to
1147 avoid extra traffic, when possible, so avoid syncing the thread
1148 list with the target, and instead go ahead and delete all threads
1149 of the process but one that reported the event. Note this must
1150 be done before calling update_breakpoints_after_exec, as
1151 otherwise clearing the threads' resources would reference stale
1152 thread breakpoints -- it may have been one of these threads that
1153 stepped across the exec. We could just clear their stepping
1154 states, but as long as we're iterating, might as well delete
1155 them. Deleting them now rather than at the next user-visible
1156 stop provides a nicer sequence of events for user and MI
1158 for (thread_info
*th
: all_threads_safe ())
1159 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1162 /* We also need to clear any left over stale state for the
1163 leader/event thread. E.g., if there was any step-resume
1164 breakpoint or similar, it's gone now. We cannot truly
1165 step-to-next statement through an exec(). */
1166 thread_info
*th
= inferior_thread ();
1167 th
->control
.step_resume_breakpoint
= NULL
;
1168 th
->control
.exception_resume_breakpoint
= NULL
;
1169 th
->control
.single_step_breakpoints
= NULL
;
1170 th
->control
.step_range_start
= 0;
1171 th
->control
.step_range_end
= 0;
1173 /* The user may have had the main thread held stopped in the
1174 previous image (e.g., schedlock on, or non-stop). Release
1176 th
->stop_requested
= 0;
1178 update_breakpoints_after_exec ();
1180 /* What is this a.out's name? */
1181 process_ptid
= ptid_t (pid
);
1182 printf_unfiltered (_("%s is executing new program: %s\n"),
1183 target_pid_to_str (process_ptid
).c_str (),
1186 /* We've followed the inferior through an exec. Therefore, the
1187 inferior has essentially been killed & reborn. */
1189 breakpoint_init_inferior (inf_execd
);
1191 gdb::unique_xmalloc_ptr
<char> exec_file_host
1192 = exec_file_find (exec_file_target
, NULL
);
1194 /* If we were unable to map the executable target pathname onto a host
1195 pathname, tell the user that. Otherwise GDB's subsequent behavior
1196 is confusing. Maybe it would even be better to stop at this point
1197 so that the user can specify a file manually before continuing. */
1198 if (exec_file_host
== NULL
)
1199 warning (_("Could not load symbols for executable %s.\n"
1200 "Do you need \"set sysroot\"?"),
1203 /* Reset the shared library package. This ensures that we get a
1204 shlib event when the child reaches "_start", at which point the
1205 dld will have had a chance to initialize the child. */
1206 /* Also, loading a symbol file below may trigger symbol lookups, and
1207 we don't want those to be satisfied by the libraries of the
1208 previous incarnation of this process. */
1209 no_shared_libraries (NULL
, 0);
1211 if (follow_exec_mode_string
== follow_exec_mode_new
)
1213 /* The user wants to keep the old inferior and program spaces
1214 around. Create a new fresh one, and switch to it. */
1216 /* Do exit processing for the original inferior before setting the new
1217 inferior's pid. Having two inferiors with the same pid would confuse
1218 find_inferior_p(t)id. Transfer the terminal state and info from the
1219 old to the new inferior. */
1220 inf
= add_inferior_with_spaces ();
1221 swap_terminal_info (inf
, current_inferior ());
1222 exit_inferior_silent (current_inferior ());
1225 target_follow_exec (inf
, exec_file_target
);
1227 inferior
*org_inferior
= current_inferior ();
1228 switch_to_inferior_no_thread (inf
);
1229 push_target (org_inferior
->process_target ());
1230 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1231 switch_to_thread (thr
);
1235 /* The old description may no longer be fit for the new image.
1236 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1237 old description; we'll read a new one below. No need to do
1238 this on "follow-exec-mode new", as the old inferior stays
1239 around (its description is later cleared/refetched on
1241 target_clear_description ();
1244 gdb_assert (current_program_space
== inf
->pspace
);
1246 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1247 because the proper displacement for a PIE (Position Independent
1248 Executable) main symbol file will only be computed by
1249 solib_create_inferior_hook below. breakpoint_re_set would fail
1250 to insert the breakpoints with the zero displacement. */
1251 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1253 /* If the target can specify a description, read it. Must do this
1254 after flipping to the new executable (because the target supplied
1255 description must be compatible with the executable's
1256 architecture, and the old executable may e.g., be 32-bit, while
1257 the new one 64-bit), and before anything involving memory or
1259 target_find_description ();
1261 solib_create_inferior_hook (0);
1263 jit_inferior_created_hook ();
1265 breakpoint_re_set ();
1267 /* Reinsert all breakpoints. (Those which were symbolic have
1268 been reset to the proper address in the new a.out, thanks
1269 to symbol_file_command...). */
1270 insert_breakpoints ();
1272 gdb::observers::inferior_execd
.notify (inf
);
1274 /* The next resume of this inferior should bring it to the shlib
1275 startup breakpoints. (If the user had also set bp's on
1276 "main" from the old (parent) process, then they'll auto-
1277 matically get reset there in the new process.). */
1280 /* The queue of threads that need to do a step-over operation to get
1281 past e.g., a breakpoint. What technique is used to step over the
1282 breakpoint/watchpoint does not matter -- all threads end up in the
1283 same queue, to maintain rough temporal order of execution, in order
1284 to avoid starvation, otherwise, we could e.g., find ourselves
1285 constantly stepping the same couple threads past their breakpoints
1286 over and over, if the single-step finish fast enough. */
1287 struct thread_info
*global_thread_step_over_chain_head
;
1289 /* Bit flags indicating what the thread needs to step over. */
1291 enum step_over_what_flag
1293 /* Step over a breakpoint. */
1294 STEP_OVER_BREAKPOINT
= 1,
1296 /* Step past a non-continuable watchpoint, in order to let the
1297 instruction execute so we can evaluate the watchpoint
1299 STEP_OVER_WATCHPOINT
= 2
1301 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1303 /* Info about an instruction that is being stepped over. */
1305 struct step_over_info
1307 /* If we're stepping past a breakpoint, this is the address space
1308 and address of the instruction the breakpoint is set at. We'll
1309 skip inserting all breakpoints here. Valid iff ASPACE is
1311 const address_space
*aspace
;
1314 /* The instruction being stepped over triggers a nonsteppable
1315 watchpoint. If true, we'll skip inserting watchpoints. */
1316 int nonsteppable_watchpoint_p
;
1318 /* The thread's global number. */
1322 /* The step-over info of the location that is being stepped over.
1324 Note that with async/breakpoint always-inserted mode, a user might
1325 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1326 being stepped over. As setting a new breakpoint inserts all
1327 breakpoints, we need to make sure the breakpoint being stepped over
1328 isn't inserted then. We do that by only clearing the step-over
1329 info when the step-over is actually finished (or aborted).
1331 Presently GDB can only step over one breakpoint at any given time.
1332 Given threads that can't run code in the same address space as the
1333 breakpoint's can't really miss the breakpoint, GDB could be taught
1334 to step-over at most one breakpoint per address space (so this info
1335 could move to the address space object if/when GDB is extended).
1336 The set of breakpoints being stepped over will normally be much
1337 smaller than the set of all breakpoints, so a flag in the
1338 breakpoint location structure would be wasteful. A separate list
1339 also saves complexity and run-time, as otherwise we'd have to go
1340 through all breakpoint locations clearing their flag whenever we
1341 start a new sequence. Similar considerations weigh against storing
1342 this info in the thread object. Plus, not all step overs actually
1343 have breakpoint locations -- e.g., stepping past a single-step
1344 breakpoint, or stepping to complete a non-continuable
1346 static struct step_over_info step_over_info
;
1348 /* Record the address of the breakpoint/instruction we're currently
1350 N.B. We record the aspace and address now, instead of say just the thread,
1351 because when we need the info later the thread may be running. */
1354 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1355 int nonsteppable_watchpoint_p
,
1358 step_over_info
.aspace
= aspace
;
1359 step_over_info
.address
= address
;
1360 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1361 step_over_info
.thread
= thread
;
1364 /* Called when we're not longer stepping over a breakpoint / an
1365 instruction, so all breakpoints are free to be (re)inserted. */
1368 clear_step_over_info (void)
1370 infrun_log_debug ("clearing step over info");
1371 step_over_info
.aspace
= NULL
;
1372 step_over_info
.address
= 0;
1373 step_over_info
.nonsteppable_watchpoint_p
= 0;
1374 step_over_info
.thread
= -1;
1380 stepping_past_instruction_at (struct address_space
*aspace
,
1383 return (step_over_info
.aspace
!= NULL
1384 && breakpoint_address_match (aspace
, address
,
1385 step_over_info
.aspace
,
1386 step_over_info
.address
));
1392 thread_is_stepping_over_breakpoint (int thread
)
1394 return (step_over_info
.thread
!= -1
1395 && thread
== step_over_info
.thread
);
1401 stepping_past_nonsteppable_watchpoint (void)
1403 return step_over_info
.nonsteppable_watchpoint_p
;
1406 /* Returns true if step-over info is valid. */
1409 step_over_info_valid_p (void)
1411 return (step_over_info
.aspace
!= NULL
1412 || stepping_past_nonsteppable_watchpoint ());
1416 /* Displaced stepping. */
1418 /* In non-stop debugging mode, we must take special care to manage
1419 breakpoints properly; in particular, the traditional strategy for
1420 stepping a thread past a breakpoint it has hit is unsuitable.
1421 'Displaced stepping' is a tactic for stepping one thread past a
1422 breakpoint it has hit while ensuring that other threads running
1423 concurrently will hit the breakpoint as they should.
1425 The traditional way to step a thread T off a breakpoint in a
1426 multi-threaded program in all-stop mode is as follows:
1428 a0) Initially, all threads are stopped, and breakpoints are not
1430 a1) We single-step T, leaving breakpoints uninserted.
1431 a2) We insert breakpoints, and resume all threads.
1433 In non-stop debugging, however, this strategy is unsuitable: we
1434 don't want to have to stop all threads in the system in order to
1435 continue or step T past a breakpoint. Instead, we use displaced
1438 n0) Initially, T is stopped, other threads are running, and
1439 breakpoints are inserted.
1440 n1) We copy the instruction "under" the breakpoint to a separate
1441 location, outside the main code stream, making any adjustments
1442 to the instruction, register, and memory state as directed by
1444 n2) We single-step T over the instruction at its new location.
1445 n3) We adjust the resulting register and memory state as directed
1446 by T's architecture. This includes resetting T's PC to point
1447 back into the main instruction stream.
1450 This approach depends on the following gdbarch methods:
1452 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1453 indicate where to copy the instruction, and how much space must
1454 be reserved there. We use these in step n1.
1456 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1457 address, and makes any necessary adjustments to the instruction,
1458 register contents, and memory. We use this in step n1.
1460 - gdbarch_displaced_step_fixup adjusts registers and memory after
1461 we have successfully single-stepped the instruction, to yield the
1462 same effect the instruction would have had if we had executed it
1463 at its original address. We use this in step n3.
1465 The gdbarch_displaced_step_copy_insn and
1466 gdbarch_displaced_step_fixup functions must be written so that
1467 copying an instruction with gdbarch_displaced_step_copy_insn,
1468 single-stepping across the copied instruction, and then applying
1469 gdbarch_displaced_insn_fixup should have the same effects on the
1470 thread's memory and registers as stepping the instruction in place
1471 would have. Exactly which responsibilities fall to the copy and
1472 which fall to the fixup is up to the author of those functions.
1474 See the comments in gdbarch.sh for details.
1476 Note that displaced stepping and software single-step cannot
1477 currently be used in combination, although with some care I think
1478 they could be made to. Software single-step works by placing
1479 breakpoints on all possible subsequent instructions; if the
1480 displaced instruction is a PC-relative jump, those breakpoints
1481 could fall in very strange places --- on pages that aren't
1482 executable, or at addresses that are not proper instruction
1483 boundaries. (We do generally let other threads run while we wait
1484 to hit the software single-step breakpoint, and they might
1485 encounter such a corrupted instruction.) One way to work around
1486 this would be to have gdbarch_displaced_step_copy_insn fully
1487 simulate the effect of PC-relative instructions (and return NULL)
1488 on architectures that use software single-stepping.
1490 In non-stop mode, we can have independent and simultaneous step
1491 requests, so more than one thread may need to simultaneously step
1492 over a breakpoint. The current implementation assumes there is
1493 only one scratch space per process. In this case, we have to
1494 serialize access to the scratch space. If thread A wants to step
1495 over a breakpoint, but we are currently waiting for some other
1496 thread to complete a displaced step, we leave thread A stopped and
1497 place it in the displaced_step_request_queue. Whenever a displaced
1498 step finishes, we pick the next thread in the queue and start a new
1499 displaced step operation on it. See displaced_step_prepare and
1500 displaced_step_fixup for details. */
1502 /* Get the displaced stepping state of inferior INF. */
1504 static displaced_step_inferior_state
*
1505 get_displaced_stepping_state (inferior
*inf
)
1507 return &inf
->displaced_step_state
;
1510 /* Get the displaced stepping state of thread THREAD. */
1512 static displaced_step_thread_state
*
1513 get_displaced_stepping_state (thread_info
*thread
)
1515 return &thread
->displaced_step_state
;
1518 /* Return true if the given thread is doing a displaced step. */
1521 displaced_step_in_progress (thread_info
*thread
)
1523 gdb_assert (thread
!= NULL
);
1525 return get_displaced_stepping_state (thread
)->in_progress ();
1528 /* Return true if any thread of this inferior is doing a displaced step. */
1531 displaced_step_in_progress (inferior
*inf
)
1533 for (thread_info
*thread
: inf
->non_exited_threads ())
1535 if (displaced_step_in_progress (thread
))
1542 /* Return true if any thread is doing a displaced step. */
1545 displaced_step_in_progress_any_thread ()
1547 for (thread_info
*thread
: all_non_exited_threads ())
1549 if (displaced_step_in_progress (thread
))
1556 /* If inferior is in displaced stepping, and ADDR equals to starting address
1557 of copy area, return corresponding displaced_step_copy_insn_closure. Otherwise,
1560 struct displaced_step_copy_insn_closure
*
1561 get_displaced_step_copy_insn_closure_by_addr (CORE_ADDR addr
)
1563 // FIXME: implement me (only needed on ARM).
1564 // displaced_step_inferior_state *displaced
1565 // = get_displaced_stepping_state (current_inferior ());
1567 // /* If checking the mode of displaced instruction in copy area. */
1568 // if (displaced->step_thread != nullptr
1569 // && displaced->step_copy == addr)
1570 // return displaced->step_closure.get ();
1576 infrun_inferior_exit (struct inferior
*inf
)
1578 inf
->displaced_step_state
.reset ();
1581 /* If ON, and the architecture supports it, GDB will use displaced
1582 stepping to step over breakpoints. If OFF, or if the architecture
1583 doesn't support it, GDB will instead use the traditional
1584 hold-and-step approach. If AUTO (which is the default), GDB will
1585 decide which technique to use to step over breakpoints depending on
1586 whether the target works in a non-stop way (see use_displaced_stepping). */
1588 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1591 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1592 struct cmd_list_element
*c
,
1595 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1596 fprintf_filtered (file
,
1597 _("Debugger's willingness to use displaced stepping "
1598 "to step over breakpoints is %s (currently %s).\n"),
1599 value
, target_is_non_stop_p () ? "on" : "off");
1601 fprintf_filtered (file
,
1602 _("Debugger's willingness to use displaced stepping "
1603 "to step over breakpoints is %s.\n"), value
);
1606 /* Return true if the gdbarch implements the required methods to use
1607 displaced stepping. */
1610 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1612 /* Only check for the presence of copy_insn. Other required methods
1613 are checked by the gdbarch validation to be provided if copy_insn is
1615 return gdbarch_displaced_step_copy_insn_p (arch
);
1618 /* Return non-zero if displaced stepping can/should be used to step
1619 over breakpoints of thread TP. */
1622 use_displaced_stepping (thread_info
*tp
)
1624 /* If the user disabled it explicitly, don't use displaced stepping. */
1625 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1628 /* If "auto", only use displaced stepping if the target operates in a non-stop
1630 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1631 && !target_is_non_stop_p ())
1634 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1636 /* If the architecture doesn't implement displaced stepping, don't use
1638 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1641 /* If recording, don't use displaced stepping. */
1642 if (find_record_target () != nullptr)
1645 displaced_step_inferior_state
*displaced_state
1646 = get_displaced_stepping_state (tp
->inf
);
1648 /* If displaced stepping failed before for this inferior, don't bother trying
1650 if (displaced_state
->failed_before
)
1656 /* Simple function wrapper around displaced_step_thread_state::reset. */
1659 displaced_step_reset (displaced_step_thread_state
*displaced
)
1661 displaced
->reset ();
1664 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1665 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1667 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1669 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1671 displaced_step_dump_bytes (struct ui_file
*file
,
1672 const gdb_byte
*buf
,
1677 for (i
= 0; i
< len
; i
++)
1678 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1679 fputs_unfiltered ("\n", file
);
1682 /* Prepare to single-step, using displaced stepping.
1684 Note that we cannot use displaced stepping when we have a signal to
1685 deliver. If we have a signal to deliver and an instruction to step
1686 over, then after the step, there will be no indication from the
1687 target whether the thread entered a signal handler or ignored the
1688 signal and stepped over the instruction successfully --- both cases
1689 result in a simple SIGTRAP. In the first case we mustn't do a
1690 fixup, and in the second case we must --- but we can't tell which.
1691 Comments in the code for 'random signals' in handle_inferior_event
1692 explain how we handle this case instead.
1694 Returns 1 if preparing was successful -- this thread is going to be
1695 stepped now; 0 if displaced stepping this thread got queued; or -1
1696 if this instruction can't be displaced stepped. */
1698 static displaced_step_prepare_status
1699 displaced_step_prepare_throw (thread_info
*tp
)
1701 regcache
*regcache
= get_thread_regcache (tp
);
1702 struct gdbarch
*gdbarch
= regcache
->arch ();
1703 displaced_step_thread_state
*thread_disp_step_state
1704 = get_displaced_stepping_state (tp
);
1706 /* We should never reach this function if the architecture does not
1707 support displaced stepping. */
1708 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1710 /* Nor if the thread isn't meant to step over a breakpoint. */
1711 gdb_assert (tp
->control
.trap_expected
);
1713 /* Disable range stepping while executing in the scratch pad. We
1714 want a single-step even if executing the displaced instruction in
1715 the scratch buffer lands within the stepping range (e.g., a
1717 tp
->control
.may_range_step
= 0;
1719 /* We are about to start a displaced step for this thread, if one is already
1720 in progress, we goofed up somewhere. */
1721 gdb_assert (!thread_disp_step_state
->in_progress ());
1723 scoped_restore_current_thread restore_thread
;
1725 switch_to_thread (tp
);
1727 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1729 displaced_step_prepare_status status
=
1730 tp
->inf
->top_target ()->displaced_step_prepare (tp
);
1732 if (status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
1734 if (debug_displaced
)
1735 fprintf_unfiltered (gdb_stdlog
,
1736 "displaced: failed to prepare (%s)",
1737 target_pid_to_str (tp
->ptid
).c_str ());
1739 return DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1741 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1743 /* Not enough displaced stepping resources available, defer this
1744 request by placing it the queue. */
1746 if (debug_displaced
)
1747 fprintf_unfiltered (gdb_stdlog
,
1748 "displaced: not enough resources available, "
1749 "deferring step of %s\n",
1750 target_pid_to_str (tp
->ptid
).c_str ());
1752 global_thread_step_over_chain_enqueue (tp
);
1753 tp
->inf
->displaced_step_state
.unavailable
= true;
1755 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1758 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1760 // FIXME: Should probably replicated in the arch implementation now.
1762 // if (breakpoint_in_range_p (aspace, copy, len))
1764 // /* There's a breakpoint set in the scratch pad location range
1765 // (which is usually around the entry point). We'd either
1766 // install it before resuming, which would overwrite/corrupt the
1767 // scratch pad, or if it was already inserted, this displaced
1768 // step would overwrite it. The latter is OK in the sense that
1769 // we already assume that no thread is going to execute the code
1770 // in the scratch pad range (after initial startup) anyway, but
1771 // the former is unacceptable. Simply punt and fallback to
1772 // stepping over this breakpoint in-line. */
1773 // if (debug_displaced)
1775 // fprintf_unfiltered (gdb_stdlog,
1776 // "displaced: breakpoint set in scratch pad. "
1777 // "Stepping over breakpoint in-line instead.\n");
1780 // gdb_assert (false);
1781 // gdbarch_displaced_step_release_location (gdbarch, copy);
1786 /* Save the information we need to fix things up if the step
1788 thread_disp_step_state
->set (gdbarch
);
1790 // FIXME: get it from _prepare?
1791 CORE_ADDR displaced_pc
= 0;
1793 if (debug_displaced
)
1794 fprintf_unfiltered (gdb_stdlog
,
1795 "displaced: prepared successfully thread=%s, "
1796 "original_pc=%s, displaced_pc=%s\n",
1797 target_pid_to_str (tp
->ptid
).c_str (),
1798 paddress (gdbarch
, original_pc
),
1799 paddress (gdbarch
, displaced_pc
));
1801 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1804 /* Wrapper for displaced_step_prepare_throw that disabled further
1805 attempts at displaced stepping if we get a memory error. */
1807 static displaced_step_prepare_status
1808 displaced_step_prepare (thread_info
*thread
)
1810 displaced_step_prepare_status status
1811 = DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1815 status
= displaced_step_prepare_throw (thread
);
1817 catch (const gdb_exception_error
&ex
)
1819 struct displaced_step_inferior_state
*displaced_state
;
1821 if (ex
.error
!= MEMORY_ERROR
1822 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1825 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1828 /* Be verbose if "set displaced-stepping" is "on", silent if
1830 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1832 warning (_("disabling displaced stepping: %s"),
1836 /* Disable further displaced stepping attempts. */
1838 = get_displaced_stepping_state (thread
->inf
);
1839 displaced_state
->failed_before
= 1;
1845 /* If we displaced stepped an instruction successfully, adjust
1846 registers and memory to yield the same effect the instruction would
1847 have had if we had executed it at its original address, and return
1848 1. If the instruction didn't complete, relocate the PC and return
1849 -1. If the thread wasn't displaced stepping, return 0. */
1852 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1854 displaced_step_thread_state
*displaced
1855 = get_displaced_stepping_state (event_thread
);
1857 /* Was this thread performing a displaced step? */
1858 if (!displaced
->in_progress ())
1861 displaced_step_reset_cleanup
cleanup (displaced
);
1863 /* Fixup may need to read memory/registers. Switch to the thread
1864 that we're fixing up. Also, target_stopped_by_watchpoint checks
1865 the current thread, and displaced_step_restore performs ptid-dependent
1866 memory accesses using current_inferior() and current_top_target(). */
1867 switch_to_thread (event_thread
);
1869 /* Do the fixup, and release the resources acquired to do the displaced
1871 displaced_step_finish_status finish_status
=
1872 event_thread
->inf
->top_target ()->displaced_step_finish (event_thread
,
1875 if (finish_status
== DISPLACED_STEP_FINISH_STATUS_OK
)
1881 /* Data to be passed around while handling an event. This data is
1882 discarded between events. */
1883 struct execution_control_state
1885 process_stratum_target
*target
;
1887 /* The thread that got the event, if this was a thread event; NULL
1889 struct thread_info
*event_thread
;
1891 struct target_waitstatus ws
;
1892 int stop_func_filled_in
;
1893 CORE_ADDR stop_func_start
;
1894 CORE_ADDR stop_func_end
;
1895 const char *stop_func_name
;
1898 /* True if the event thread hit the single-step breakpoint of
1899 another thread. Thus the event doesn't cause a stop, the thread
1900 needs to be single-stepped past the single-step breakpoint before
1901 we can switch back to the original stepping thread. */
1902 int hit_singlestep_breakpoint
;
1905 /* Clear ECS and set it to point at TP. */
1908 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1910 memset (ecs
, 0, sizeof (*ecs
));
1911 ecs
->event_thread
= tp
;
1912 ecs
->ptid
= tp
->ptid
;
1915 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1916 static void prepare_to_wait (struct execution_control_state
*ecs
);
1917 static int keep_going_stepped_thread (struct thread_info
*tp
);
1918 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1920 /* Are there any pending step-over requests? If so, run all we can
1921 now and return true. Otherwise, return false. */
1924 start_step_over (void)
1926 struct thread_info
*tp
, *next
;
1929 /* Don't start a new step-over if we already have an in-line
1930 step-over operation ongoing. */
1931 if (step_over_info_valid_p ())
1934 /* Steal the global thread step over chain. */
1935 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1936 global_thread_step_over_chain_head
= NULL
;
1939 fprintf_unfiltered (gdb_stdlog
,
1940 "infrun: stealing list of %d threads to step from global queue\n",
1941 thread_step_over_chain_length (threads_to_step
));
1943 for (inferior
*inf
: all_inferiors ())
1944 inf
->displaced_step_state
.unavailable
= false;
1946 for (tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1948 struct execution_control_state ecss
;
1949 struct execution_control_state
*ecs
= &ecss
;
1950 step_over_what step_what
;
1951 int must_be_in_line
;
1953 gdb_assert (!tp
->stop_requested
);
1955 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1957 step_what
= thread_still_needs_step_over (tp
);
1958 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1959 || ((step_what
& STEP_OVER_BREAKPOINT
)
1960 && !use_displaced_stepping (tp
)));
1962 /* We currently stop all threads of all processes to step-over
1963 in-line. If we need to start a new in-line step-over, let
1964 any pending displaced steps finish first. */
1965 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1968 thread_step_over_chain_remove (&threads_to_step
, tp
);
1970 if (tp
->control
.trap_expected
1974 internal_error (__FILE__
, __LINE__
,
1975 "[%s] has inconsistent state: "
1976 "trap_expected=%d, resumed=%d, executing=%d\n",
1977 target_pid_to_str (tp
->ptid
).c_str (),
1978 tp
->control
.trap_expected
,
1983 infrun_log_debug ("resuming [%s] for step-over",
1984 target_pid_to_str (tp
->ptid
).c_str ());
1986 /* keep_going_pass_signal skips the step-over if the breakpoint
1987 is no longer inserted. In all-stop, we want to keep looking
1988 for a thread that needs a step-over instead of resuming TP,
1989 because we wouldn't be able to resume anything else until the
1990 target stops again. In non-stop, the resume always resumes
1991 only TP, so it's OK to let the thread resume freely. */
1992 if (!target_is_non_stop_p () && !step_what
)
1995 if (tp
->inf
->displaced_step_state
.unavailable
)
1997 global_thread_step_over_chain_enqueue (tp
);
2001 switch_to_thread (tp
);
2002 reset_ecs (ecs
, tp
);
2003 keep_going_pass_signal (ecs
);
2005 if (!ecs
->wait_some_more
)
2006 error (_("Command aborted."));
2008 /* If the thread's step over could not be initiated, it was re-added
2009 to the global step over chain. */
2012 infrun_log_debug ("start_step_over: [%s] was resumed.\n",
2013 target_pid_to_str (tp
->ptid
).c_str ());
2014 gdb_assert (!thread_is_in_step_over_chain (tp
));
2018 infrun_log_debug ("infrun: start_step_over: [%s] was NOT resumed.\n",
2019 target_pid_to_str (tp
->ptid
).c_str ());
2020 gdb_assert (thread_is_in_step_over_chain (tp
));
2024 /* If we started a new in-line step-over, we're done. */
2025 if (step_over_info_valid_p ())
2027 gdb_assert (tp
->control
.trap_expected
);
2032 if (!target_is_non_stop_p ())
2034 /* On all-stop, shouldn't have resumed unless we needed a
2036 gdb_assert (tp
->control
.trap_expected
2037 || tp
->step_after_step_resume_breakpoint
);
2039 /* With remote targets (at least), in all-stop, we can't
2040 issue any further remote commands until the program stops
2046 /* Either the thread no longer needed a step-over, or a new
2047 displaced stepping sequence started. Even in the latter
2048 case, continue looking. Maybe we can also start another
2049 displaced step on a thread of other process. */
2052 /* If there are threads left in the THREADS_TO_STEP list, but we have
2053 detected that we can't start anything more, put back these threads
2054 in the global list. */
2055 if (threads_to_step
== NULL
)
2058 fprintf_unfiltered (gdb_stdlog
,
2059 "infrun: step-over queue now empty\n");
2064 fprintf_unfiltered (gdb_stdlog
,
2065 "infrun: putting back %d threads to step in global queue\n",
2066 thread_step_over_chain_length (threads_to_step
));
2067 while (threads_to_step
!= nullptr)
2069 thread_info
*thread
= threads_to_step
;
2071 /* Remove from that list. */
2072 thread_step_over_chain_remove (&threads_to_step
, thread
);
2074 /* Add to global list. */
2075 global_thread_step_over_chain_enqueue (thread
);
2083 /* Update global variables holding ptids to hold NEW_PTID if they were
2084 holding OLD_PTID. */
2086 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2088 if (inferior_ptid
== old_ptid
)
2089 inferior_ptid
= new_ptid
;
2094 static const char schedlock_off
[] = "off";
2095 static const char schedlock_on
[] = "on";
2096 static const char schedlock_step
[] = "step";
2097 static const char schedlock_replay
[] = "replay";
2098 static const char *const scheduler_enums
[] = {
2105 static const char *scheduler_mode
= schedlock_replay
;
2107 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2108 struct cmd_list_element
*c
, const char *value
)
2110 fprintf_filtered (file
,
2111 _("Mode for locking scheduler "
2112 "during execution is \"%s\".\n"),
2117 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2119 if (!target_can_lock_scheduler
)
2121 scheduler_mode
= schedlock_off
;
2122 error (_("Target '%s' cannot support this command."), target_shortname
);
2126 /* True if execution commands resume all threads of all processes by
2127 default; otherwise, resume only threads of the current inferior
2129 bool sched_multi
= false;
2131 /* Try to setup for software single stepping over the specified location.
2132 Return 1 if target_resume() should use hardware single step.
2134 GDBARCH the current gdbarch.
2135 PC the location to step over. */
2138 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2142 if (execution_direction
== EXEC_FORWARD
2143 && gdbarch_software_single_step_p (gdbarch
))
2144 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2152 user_visible_resume_ptid (int step
)
2158 /* With non-stop mode on, threads are always handled
2160 resume_ptid
= inferior_ptid
;
2162 else if ((scheduler_mode
== schedlock_on
)
2163 || (scheduler_mode
== schedlock_step
&& step
))
2165 /* User-settable 'scheduler' mode requires solo thread
2167 resume_ptid
= inferior_ptid
;
2169 else if ((scheduler_mode
== schedlock_replay
)
2170 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2172 /* User-settable 'scheduler' mode requires solo thread resume in replay
2174 resume_ptid
= inferior_ptid
;
2176 else if (!sched_multi
&& target_supports_multi_process ())
2178 /* Resume all threads of the current process (and none of other
2180 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2184 /* Resume all threads of all processes. */
2185 resume_ptid
= RESUME_ALL
;
2193 process_stratum_target
*
2194 user_visible_resume_target (ptid_t resume_ptid
)
2196 return (resume_ptid
== minus_one_ptid
&& sched_multi
2198 : current_inferior ()->process_target ());
2201 /* Return a ptid representing the set of threads that we will resume,
2202 in the perspective of the target, assuming run control handling
2203 does not require leaving some threads stopped (e.g., stepping past
2204 breakpoint). USER_STEP indicates whether we're about to start the
2205 target for a stepping command. */
2208 internal_resume_ptid (int user_step
)
2210 /* In non-stop, we always control threads individually. Note that
2211 the target may always work in non-stop mode even with "set
2212 non-stop off", in which case user_visible_resume_ptid could
2213 return a wildcard ptid. */
2214 if (target_is_non_stop_p ())
2215 return inferior_ptid
;
2217 return user_visible_resume_ptid (user_step
);
2220 /* Wrapper for target_resume, that handles infrun-specific
2224 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2226 struct thread_info
*tp
= inferior_thread ();
2228 gdb_assert (!tp
->stop_requested
);
2230 /* Install inferior's terminal modes. */
2231 target_terminal::inferior ();
2233 /* Avoid confusing the next resume, if the next stop/resume
2234 happens to apply to another thread. */
2235 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2237 /* Advise target which signals may be handled silently.
2239 If we have removed breakpoints because we are stepping over one
2240 in-line (in any thread), we need to receive all signals to avoid
2241 accidentally skipping a breakpoint during execution of a signal
2244 Likewise if we're displaced stepping, otherwise a trap for a
2245 breakpoint in a signal handler might be confused with the
2246 displaced step finishing. We don't make the displaced_step_fixup
2247 step distinguish the cases instead, because:
2249 - a backtrace while stopped in the signal handler would show the
2250 scratch pad as frame older than the signal handler, instead of
2251 the real mainline code.
2253 - when the thread is later resumed, the signal handler would
2254 return to the scratch pad area, which would no longer be
2256 if (step_over_info_valid_p ()
2257 || displaced_step_in_progress (tp
->inf
))
2258 target_pass_signals ({});
2260 target_pass_signals (signal_pass
);
2262 target_resume (resume_ptid
, step
, sig
);
2264 target_commit_resume ();
2266 if (target_can_async_p ())
2270 /* Resume the inferior. SIG is the signal to give the inferior
2271 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2272 call 'resume', which handles exceptions. */
2275 resume_1 (enum gdb_signal sig
)
2277 struct regcache
*regcache
= get_current_regcache ();
2278 struct gdbarch
*gdbarch
= regcache
->arch ();
2279 struct thread_info
*tp
= inferior_thread ();
2280 const address_space
*aspace
= regcache
->aspace ();
2282 /* This represents the user's step vs continue request. When
2283 deciding whether "set scheduler-locking step" applies, it's the
2284 user's intention that counts. */
2285 const int user_step
= tp
->control
.stepping_command
;
2286 /* This represents what we'll actually request the target to do.
2287 This can decay from a step to a continue, if e.g., we need to
2288 implement single-stepping with breakpoints (software
2292 gdb_assert (!tp
->stop_requested
);
2293 gdb_assert (!thread_is_in_step_over_chain (tp
));
2295 if (tp
->suspend
.waitstatus_pending_p
)
2298 ("thread %s has pending wait "
2299 "status %s (currently_stepping=%d).",
2300 target_pid_to_str (tp
->ptid
).c_str (),
2301 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2302 currently_stepping (tp
));
2304 tp
->inf
->process_target ()->threads_executing
= true;
2307 /* FIXME: What should we do if we are supposed to resume this
2308 thread with a signal? Maybe we should maintain a queue of
2309 pending signals to deliver. */
2310 if (sig
!= GDB_SIGNAL_0
)
2312 warning (_("Couldn't deliver signal %s to %s."),
2313 gdb_signal_to_name (sig
),
2314 target_pid_to_str (tp
->ptid
).c_str ());
2317 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2319 if (target_can_async_p ())
2322 /* Tell the event loop we have an event to process. */
2323 mark_async_event_handler (infrun_async_inferior_event_token
);
2328 tp
->stepped_breakpoint
= 0;
2330 /* Depends on stepped_breakpoint. */
2331 step
= currently_stepping (tp
);
2333 if (current_inferior ()->waiting_for_vfork_done
)
2335 /* Don't try to single-step a vfork parent that is waiting for
2336 the child to get out of the shared memory region (by exec'ing
2337 or exiting). This is particularly important on software
2338 single-step archs, as the child process would trip on the
2339 software single step breakpoint inserted for the parent
2340 process. Since the parent will not actually execute any
2341 instruction until the child is out of the shared region (such
2342 are vfork's semantics), it is safe to simply continue it.
2343 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2344 the parent, and tell it to `keep_going', which automatically
2345 re-sets it stepping. */
2346 infrun_log_debug ("resume : clear step");
2350 CORE_ADDR pc
= regcache_read_pc (regcache
);
2352 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2353 "current thread [%s] at %s",
2354 step
, gdb_signal_to_symbol_string (sig
),
2355 tp
->control
.trap_expected
,
2356 target_pid_to_str (inferior_ptid
).c_str (),
2357 paddress (gdbarch
, pc
));
2359 /* Normally, by the time we reach `resume', the breakpoints are either
2360 removed or inserted, as appropriate. The exception is if we're sitting
2361 at a permanent breakpoint; we need to step over it, but permanent
2362 breakpoints can't be removed. So we have to test for it here. */
2363 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2365 if (sig
!= GDB_SIGNAL_0
)
2367 /* We have a signal to pass to the inferior. The resume
2368 may, or may not take us to the signal handler. If this
2369 is a step, we'll need to stop in the signal handler, if
2370 there's one, (if the target supports stepping into
2371 handlers), or in the next mainline instruction, if
2372 there's no handler. If this is a continue, we need to be
2373 sure to run the handler with all breakpoints inserted.
2374 In all cases, set a breakpoint at the current address
2375 (where the handler returns to), and once that breakpoint
2376 is hit, resume skipping the permanent breakpoint. If
2377 that breakpoint isn't hit, then we've stepped into the
2378 signal handler (or hit some other event). We'll delete
2379 the step-resume breakpoint then. */
2381 infrun_log_debug ("resume: skipping permanent breakpoint, "
2382 "deliver signal first");
2384 clear_step_over_info ();
2385 tp
->control
.trap_expected
= 0;
2387 if (tp
->control
.step_resume_breakpoint
== NULL
)
2389 /* Set a "high-priority" step-resume, as we don't want
2390 user breakpoints at PC to trigger (again) when this
2392 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2393 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2395 tp
->step_after_step_resume_breakpoint
= step
;
2398 insert_breakpoints ();
2402 /* There's no signal to pass, we can go ahead and skip the
2403 permanent breakpoint manually. */
2404 infrun_log_debug ("skipping permanent breakpoint");
2405 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2406 /* Update pc to reflect the new address from which we will
2407 execute instructions. */
2408 pc
= regcache_read_pc (regcache
);
2412 /* We've already advanced the PC, so the stepping part
2413 is done. Now we need to arrange for a trap to be
2414 reported to handle_inferior_event. Set a breakpoint
2415 at the current PC, and run to it. Don't update
2416 prev_pc, because if we end in
2417 switch_back_to_stepped_thread, we want the "expected
2418 thread advanced also" branch to be taken. IOW, we
2419 don't want this thread to step further from PC
2421 gdb_assert (!step_over_info_valid_p ());
2422 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2423 insert_breakpoints ();
2425 resume_ptid
= internal_resume_ptid (user_step
);
2426 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2433 /* If we have a breakpoint to step over, make sure to do a single
2434 step only. Same if we have software watchpoints. */
2435 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2436 tp
->control
.may_range_step
= 0;
2438 /* If displaced stepping is enabled, step over breakpoints by executing a
2439 copy of the instruction at a different address.
2441 We can't use displaced stepping when we have a signal to deliver;
2442 the comments for displaced_step_prepare explain why. The
2443 comments in the handle_inferior event for dealing with 'random
2444 signals' explain what we do instead.
2446 We can't use displaced stepping when we are waiting for vfork_done
2447 event, displaced stepping breaks the vfork child similarly as single
2448 step software breakpoint. */
2449 if (tp
->control
.trap_expected
2450 && use_displaced_stepping (tp
)
2451 && !step_over_info_valid_p ()
2452 && sig
== GDB_SIGNAL_0
2453 && !current_inferior ()->waiting_for_vfork_done
)
2455 displaced_step_prepare_status prepare_status
2456 = displaced_step_prepare (tp
);
2458 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2460 infrun_log_debug ("Got placed in step-over queue");
2462 tp
->control
.trap_expected
= 0;
2465 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
2467 /* Fallback to stepping over the breakpoint in-line. */
2469 if (target_is_non_stop_p ())
2470 stop_all_threads ();
2472 set_step_over_info (regcache
->aspace (),
2473 regcache_read_pc (regcache
), 0, tp
->global_num
);
2475 step
= maybe_software_singlestep (gdbarch
, pc
);
2477 insert_breakpoints ();
2479 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2481 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
, NULL
);
2484 gdb_assert_not_reached ("invalid displaced_step_prepare_status value");
2487 /* Do we need to do it the hard way, w/temp breakpoints? */
2489 step
= maybe_software_singlestep (gdbarch
, pc
);
2491 /* Currently, our software single-step implementation leads to different
2492 results than hardware single-stepping in one situation: when stepping
2493 into delivering a signal which has an associated signal handler,
2494 hardware single-step will stop at the first instruction of the handler,
2495 while software single-step will simply skip execution of the handler.
2497 For now, this difference in behavior is accepted since there is no
2498 easy way to actually implement single-stepping into a signal handler
2499 without kernel support.
2501 However, there is one scenario where this difference leads to follow-on
2502 problems: if we're stepping off a breakpoint by removing all breakpoints
2503 and then single-stepping. In this case, the software single-step
2504 behavior means that even if there is a *breakpoint* in the signal
2505 handler, GDB still would not stop.
2507 Fortunately, we can at least fix this particular issue. We detect
2508 here the case where we are about to deliver a signal while software
2509 single-stepping with breakpoints removed. In this situation, we
2510 revert the decisions to remove all breakpoints and insert single-
2511 step breakpoints, and instead we install a step-resume breakpoint
2512 at the current address, deliver the signal without stepping, and
2513 once we arrive back at the step-resume breakpoint, actually step
2514 over the breakpoint we originally wanted to step over. */
2515 if (thread_has_single_step_breakpoints_set (tp
)
2516 && sig
!= GDB_SIGNAL_0
2517 && step_over_info_valid_p ())
2519 /* If we have nested signals or a pending signal is delivered
2520 immediately after a handler returns, might already have
2521 a step-resume breakpoint set on the earlier handler. We cannot
2522 set another step-resume breakpoint; just continue on until the
2523 original breakpoint is hit. */
2524 if (tp
->control
.step_resume_breakpoint
== NULL
)
2526 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2527 tp
->step_after_step_resume_breakpoint
= 1;
2530 delete_single_step_breakpoints (tp
);
2532 clear_step_over_info ();
2533 tp
->control
.trap_expected
= 0;
2535 insert_breakpoints ();
2538 /* If STEP is set, it's a request to use hardware stepping
2539 facilities. But in that case, we should never
2540 use singlestep breakpoint. */
2541 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2543 /* Decide the set of threads to ask the target to resume. */
2544 if (tp
->control
.trap_expected
)
2546 /* We're allowing a thread to run past a breakpoint it has
2547 hit, either by single-stepping the thread with the breakpoint
2548 removed, or by displaced stepping, with the breakpoint inserted.
2549 In the former case, we need to single-step only this thread,
2550 and keep others stopped, as they can miss this breakpoint if
2551 allowed to run. That's not really a problem for displaced
2552 stepping, but, we still keep other threads stopped, in case
2553 another thread is also stopped for a breakpoint waiting for
2554 its turn in the displaced stepping queue. */
2555 resume_ptid
= inferior_ptid
;
2558 resume_ptid
= internal_resume_ptid (user_step
);
2560 if (execution_direction
!= EXEC_REVERSE
2561 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2563 /* There are two cases where we currently need to step a
2564 breakpoint instruction when we have a signal to deliver:
2566 - See handle_signal_stop where we handle random signals that
2567 could take out us out of the stepping range. Normally, in
2568 that case we end up continuing (instead of stepping) over the
2569 signal handler with a breakpoint at PC, but there are cases
2570 where we should _always_ single-step, even if we have a
2571 step-resume breakpoint, like when a software watchpoint is
2572 set. Assuming single-stepping and delivering a signal at the
2573 same time would takes us to the signal handler, then we could
2574 have removed the breakpoint at PC to step over it. However,
2575 some hardware step targets (like e.g., Mac OS) can't step
2576 into signal handlers, and for those, we need to leave the
2577 breakpoint at PC inserted, as otherwise if the handler
2578 recurses and executes PC again, it'll miss the breakpoint.
2579 So we leave the breakpoint inserted anyway, but we need to
2580 record that we tried to step a breakpoint instruction, so
2581 that adjust_pc_after_break doesn't end up confused.
2583 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2584 in one thread after another thread that was stepping had been
2585 momentarily paused for a step-over. When we re-resume the
2586 stepping thread, it may be resumed from that address with a
2587 breakpoint that hasn't trapped yet. Seen with
2588 gdb.threads/non-stop-fair-events.exp, on targets that don't
2589 do displaced stepping. */
2591 infrun_log_debug ("resume: [%s] stepped breakpoint",
2592 target_pid_to_str (tp
->ptid
).c_str ());
2594 tp
->stepped_breakpoint
= 1;
2596 /* Most targets can step a breakpoint instruction, thus
2597 executing it normally. But if this one cannot, just
2598 continue and we will hit it anyway. */
2599 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2604 && tp
->control
.trap_expected
2605 && use_displaced_stepping (tp
)
2606 && !step_over_info_valid_p ())
2608 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2609 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2610 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2613 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2614 paddress (resume_gdbarch
, actual_pc
));
2615 read_memory (actual_pc
, buf
, sizeof (buf
));
2616 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2619 if (tp
->control
.may_range_step
)
2621 /* If we're resuming a thread with the PC out of the step
2622 range, then we're doing some nested/finer run control
2623 operation, like stepping the thread out of the dynamic
2624 linker or the displaced stepping scratch pad. We
2625 shouldn't have allowed a range step then. */
2626 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2629 do_target_resume (resume_ptid
, step
, sig
);
2633 /* Resume the inferior. SIG is the signal to give the inferior
2634 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2635 rolls back state on error. */
2638 resume (gdb_signal sig
)
2644 catch (const gdb_exception
&ex
)
2646 /* If resuming is being aborted for any reason, delete any
2647 single-step breakpoint resume_1 may have created, to avoid
2648 confusing the following resumption, and to avoid leaving
2649 single-step breakpoints perturbing other threads, in case
2650 we're running in non-stop mode. */
2651 if (inferior_ptid
!= null_ptid
)
2652 delete_single_step_breakpoints (inferior_thread ());
2662 /* Counter that tracks number of user visible stops. This can be used
2663 to tell whether a command has proceeded the inferior past the
2664 current location. This allows e.g., inferior function calls in
2665 breakpoint commands to not interrupt the command list. When the
2666 call finishes successfully, the inferior is standing at the same
2667 breakpoint as if nothing happened (and so we don't call
2669 static ULONGEST current_stop_id
;
2676 return current_stop_id
;
2679 /* Called when we report a user visible stop. */
2687 /* Clear out all variables saying what to do when inferior is continued.
2688 First do this, then set the ones you want, then call `proceed'. */
2691 clear_proceed_status_thread (struct thread_info
*tp
)
2693 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2695 /* If we're starting a new sequence, then the previous finished
2696 single-step is no longer relevant. */
2697 if (tp
->suspend
.waitstatus_pending_p
)
2699 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2701 infrun_log_debug ("pending event of %s was a finished step. "
2703 target_pid_to_str (tp
->ptid
).c_str ());
2705 tp
->suspend
.waitstatus_pending_p
= 0;
2706 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2711 ("thread %s has pending wait status %s (currently_stepping=%d).",
2712 target_pid_to_str (tp
->ptid
).c_str (),
2713 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2714 currently_stepping (tp
));
2718 /* If this signal should not be seen by program, give it zero.
2719 Used for debugging signals. */
2720 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2721 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2723 delete tp
->thread_fsm
;
2724 tp
->thread_fsm
= NULL
;
2726 tp
->control
.trap_expected
= 0;
2727 tp
->control
.step_range_start
= 0;
2728 tp
->control
.step_range_end
= 0;
2729 tp
->control
.may_range_step
= 0;
2730 tp
->control
.step_frame_id
= null_frame_id
;
2731 tp
->control
.step_stack_frame_id
= null_frame_id
;
2732 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2733 tp
->control
.step_start_function
= NULL
;
2734 tp
->stop_requested
= 0;
2736 tp
->control
.stop_step
= 0;
2738 tp
->control
.proceed_to_finish
= 0;
2740 tp
->control
.stepping_command
= 0;
2742 /* Discard any remaining commands or status from previous stop. */
2743 bpstat_clear (&tp
->control
.stop_bpstat
);
2747 clear_proceed_status (int step
)
2749 /* With scheduler-locking replay, stop replaying other threads if we're
2750 not replaying the user-visible resume ptid.
2752 This is a convenience feature to not require the user to explicitly
2753 stop replaying the other threads. We're assuming that the user's
2754 intent is to resume tracing the recorded process. */
2755 if (!non_stop
&& scheduler_mode
== schedlock_replay
2756 && target_record_is_replaying (minus_one_ptid
)
2757 && !target_record_will_replay (user_visible_resume_ptid (step
),
2758 execution_direction
))
2759 target_record_stop_replaying ();
2761 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2763 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2764 process_stratum_target
*resume_target
2765 = user_visible_resume_target (resume_ptid
);
2767 /* In all-stop mode, delete the per-thread status of all threads
2768 we're about to resume, implicitly and explicitly. */
2769 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2770 clear_proceed_status_thread (tp
);
2773 if (inferior_ptid
!= null_ptid
)
2775 struct inferior
*inferior
;
2779 /* If in non-stop mode, only delete the per-thread status of
2780 the current thread. */
2781 clear_proceed_status_thread (inferior_thread ());
2784 inferior
= current_inferior ();
2785 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2788 gdb::observers::about_to_proceed
.notify ();
2791 /* Returns true if TP is still stopped at a breakpoint that needs
2792 stepping-over in order to make progress. If the breakpoint is gone
2793 meanwhile, we can skip the whole step-over dance. */
2796 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2798 if (tp
->stepping_over_breakpoint
)
2800 struct regcache
*regcache
= get_thread_regcache (tp
);
2802 if (breakpoint_here_p (regcache
->aspace (),
2803 regcache_read_pc (regcache
))
2804 == ordinary_breakpoint_here
)
2807 tp
->stepping_over_breakpoint
= 0;
2813 /* Check whether thread TP still needs to start a step-over in order
2814 to make progress when resumed. Returns an bitwise or of enum
2815 step_over_what bits, indicating what needs to be stepped over. */
2817 static step_over_what
2818 thread_still_needs_step_over (struct thread_info
*tp
)
2820 step_over_what what
= 0;
2822 if (thread_still_needs_step_over_bp (tp
))
2823 what
|= STEP_OVER_BREAKPOINT
;
2825 if (tp
->stepping_over_watchpoint
2826 && !target_have_steppable_watchpoint
)
2827 what
|= STEP_OVER_WATCHPOINT
;
2832 /* Returns true if scheduler locking applies. STEP indicates whether
2833 we're about to do a step/next-like command to a thread. */
2836 schedlock_applies (struct thread_info
*tp
)
2838 return (scheduler_mode
== schedlock_on
2839 || (scheduler_mode
== schedlock_step
2840 && tp
->control
.stepping_command
)
2841 || (scheduler_mode
== schedlock_replay
2842 && target_record_will_replay (minus_one_ptid
,
2843 execution_direction
)));
2846 /* Calls target_commit_resume on all targets. */
2849 commit_resume_all_targets ()
2851 scoped_restore_current_thread restore_thread
;
2853 /* Map between process_target and a representative inferior. This
2854 is to avoid committing a resume in the same target more than
2855 once. Resumptions must be idempotent, so this is an
2857 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2859 for (inferior
*inf
: all_non_exited_inferiors ())
2860 if (inf
->has_execution ())
2861 conn_inf
[inf
->process_target ()] = inf
;
2863 for (const auto &ci
: conn_inf
)
2865 inferior
*inf
= ci
.second
;
2866 switch_to_inferior_no_thread (inf
);
2867 target_commit_resume ();
2871 /* Check that all the targets we're about to resume are in non-stop
2872 mode. Ideally, we'd only care whether all targets support
2873 target-async, but we're not there yet. E.g., stop_all_threads
2874 doesn't know how to handle all-stop targets. Also, the remote
2875 protocol in all-stop mode is synchronous, irrespective of
2876 target-async, which means that things like a breakpoint re-set
2877 triggered by one target would try to read memory from all targets
2881 check_multi_target_resumption (process_stratum_target
*resume_target
)
2883 if (!non_stop
&& resume_target
== nullptr)
2885 scoped_restore_current_thread restore_thread
;
2887 /* This is used to track whether we're resuming more than one
2889 process_stratum_target
*first_connection
= nullptr;
2891 /* The first inferior we see with a target that does not work in
2892 always-non-stop mode. */
2893 inferior
*first_not_non_stop
= nullptr;
2895 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2897 switch_to_inferior_no_thread (inf
);
2899 if (!target_has_execution
)
2902 process_stratum_target
*proc_target
2903 = current_inferior ()->process_target();
2905 if (!target_is_non_stop_p ())
2906 first_not_non_stop
= inf
;
2908 if (first_connection
== nullptr)
2909 first_connection
= proc_target
;
2910 else if (first_connection
!= proc_target
2911 && first_not_non_stop
!= nullptr)
2913 switch_to_inferior_no_thread (first_not_non_stop
);
2915 proc_target
= current_inferior ()->process_target();
2917 error (_("Connection %d (%s) does not support "
2918 "multi-target resumption."),
2919 proc_target
->connection_number
,
2920 make_target_connection_string (proc_target
).c_str ());
2926 /* Basic routine for continuing the program in various fashions.
2928 ADDR is the address to resume at, or -1 for resume where stopped.
2929 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2930 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2932 You should call clear_proceed_status before calling proceed. */
2935 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2937 struct regcache
*regcache
;
2938 struct gdbarch
*gdbarch
;
2940 struct execution_control_state ecss
;
2941 struct execution_control_state
*ecs
= &ecss
;
2944 /* If we're stopped at a fork/vfork, follow the branch set by the
2945 "set follow-fork-mode" command; otherwise, we'll just proceed
2946 resuming the current thread. */
2947 if (!follow_fork ())
2949 /* The target for some reason decided not to resume. */
2951 if (target_can_async_p ())
2952 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2956 /* We'll update this if & when we switch to a new thread. */
2957 previous_inferior_ptid
= inferior_ptid
;
2959 regcache
= get_current_regcache ();
2960 gdbarch
= regcache
->arch ();
2961 const address_space
*aspace
= regcache
->aspace ();
2963 pc
= regcache_read_pc_protected (regcache
);
2965 thread_info
*cur_thr
= inferior_thread ();
2967 /* Fill in with reasonable starting values. */
2968 init_thread_stepping_state (cur_thr
);
2970 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2973 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2974 process_stratum_target
*resume_target
2975 = user_visible_resume_target (resume_ptid
);
2977 check_multi_target_resumption (resume_target
);
2979 if (addr
== (CORE_ADDR
) -1)
2981 if (pc
== cur_thr
->suspend
.stop_pc
2982 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2983 && execution_direction
!= EXEC_REVERSE
)
2984 /* There is a breakpoint at the address we will resume at,
2985 step one instruction before inserting breakpoints so that
2986 we do not stop right away (and report a second hit at this
2989 Note, we don't do this in reverse, because we won't
2990 actually be executing the breakpoint insn anyway.
2991 We'll be (un-)executing the previous instruction. */
2992 cur_thr
->stepping_over_breakpoint
= 1;
2993 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2994 && gdbarch_single_step_through_delay (gdbarch
,
2995 get_current_frame ()))
2996 /* We stepped onto an instruction that needs to be stepped
2997 again before re-inserting the breakpoint, do so. */
2998 cur_thr
->stepping_over_breakpoint
= 1;
3002 regcache_write_pc (regcache
, addr
);
3005 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3006 cur_thr
->suspend
.stop_signal
= siggnal
;
3008 /* If an exception is thrown from this point on, make sure to
3009 propagate GDB's knowledge of the executing state to the
3010 frontend/user running state. */
3011 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3013 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3014 threads (e.g., we might need to set threads stepping over
3015 breakpoints first), from the user/frontend's point of view, all
3016 threads in RESUME_PTID are now running. Unless we're calling an
3017 inferior function, as in that case we pretend the inferior
3018 doesn't run at all. */
3019 if (!cur_thr
->control
.in_infcall
)
3020 set_running (resume_target
, resume_ptid
, true);
3022 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3023 gdb_signal_to_symbol_string (siggnal
));
3025 annotate_starting ();
3027 /* Make sure that output from GDB appears before output from the
3029 gdb_flush (gdb_stdout
);
3031 /* Since we've marked the inferior running, give it the terminal. A
3032 QUIT/Ctrl-C from here on is forwarded to the target (which can
3033 still detect attempts to unblock a stuck connection with repeated
3034 Ctrl-C from within target_pass_ctrlc). */
3035 target_terminal::inferior ();
3037 /* In a multi-threaded task we may select another thread and
3038 then continue or step.
3040 But if a thread that we're resuming had stopped at a breakpoint,
3041 it will immediately cause another breakpoint stop without any
3042 execution (i.e. it will report a breakpoint hit incorrectly). So
3043 we must step over it first.
3045 Look for threads other than the current (TP) that reported a
3046 breakpoint hit and haven't been resumed yet since. */
3048 /* If scheduler locking applies, we can avoid iterating over all
3050 if (!non_stop
&& !schedlock_applies (cur_thr
))
3052 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3055 switch_to_thread_no_regs (tp
);
3057 /* Ignore the current thread here. It's handled
3062 if (!thread_still_needs_step_over (tp
))
3065 gdb_assert (!thread_is_in_step_over_chain (tp
));
3067 infrun_log_debug ("need to step-over [%s] first",
3068 target_pid_to_str (tp
->ptid
).c_str ());
3070 global_thread_step_over_chain_enqueue (tp
);
3073 switch_to_thread (cur_thr
);
3076 /* Enqueue the current thread last, so that we move all other
3077 threads over their breakpoints first. */
3078 if (cur_thr
->stepping_over_breakpoint
)
3079 global_thread_step_over_chain_enqueue (cur_thr
);
3081 /* If the thread isn't started, we'll still need to set its prev_pc,
3082 so that switch_back_to_stepped_thread knows the thread hasn't
3083 advanced. Must do this before resuming any thread, as in
3084 all-stop/remote, once we resume we can't send any other packet
3085 until the target stops again. */
3086 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3089 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3091 started
= start_step_over ();
3093 if (step_over_info_valid_p ())
3095 /* Either this thread started a new in-line step over, or some
3096 other thread was already doing one. In either case, don't
3097 resume anything else until the step-over is finished. */
3099 else if (started
&& !target_is_non_stop_p ())
3101 /* A new displaced stepping sequence was started. In all-stop,
3102 we can't talk to the target anymore until it next stops. */
3104 else if (!non_stop
&& target_is_non_stop_p ())
3106 /* In all-stop, but the target is always in non-stop mode.
3107 Start all other threads that are implicitly resumed too. */
3108 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3111 switch_to_thread_no_regs (tp
);
3113 if (!tp
->inf
->has_execution ())
3115 infrun_log_debug ("[%s] target has no execution",
3116 target_pid_to_str (tp
->ptid
).c_str ());
3122 infrun_log_debug ("[%s] resumed",
3123 target_pid_to_str (tp
->ptid
).c_str ());
3124 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3128 if (thread_is_in_step_over_chain (tp
))
3130 infrun_log_debug ("[%s] needs step-over",
3131 target_pid_to_str (tp
->ptid
).c_str ());
3135 infrun_log_debug ("resuming %s",
3136 target_pid_to_str (tp
->ptid
).c_str ());
3138 reset_ecs (ecs
, tp
);
3139 switch_to_thread (tp
);
3140 keep_going_pass_signal (ecs
);
3141 if (!ecs
->wait_some_more
)
3142 error (_("Command aborted."));
3145 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3147 /* The thread wasn't started, and isn't queued, run it now. */
3148 reset_ecs (ecs
, cur_thr
);
3149 switch_to_thread (cur_thr
);
3150 keep_going_pass_signal (ecs
);
3151 if (!ecs
->wait_some_more
)
3152 error (_("Command aborted."));
3156 commit_resume_all_targets ();
3158 finish_state
.release ();
3160 /* If we've switched threads above, switch back to the previously
3161 current thread. We don't want the user to see a different
3163 switch_to_thread (cur_thr
);
3165 /* Tell the event loop to wait for it to stop. If the target
3166 supports asynchronous execution, it'll do this from within
3168 if (!target_can_async_p ())
3169 mark_async_event_handler (infrun_async_inferior_event_token
);
3173 /* Start remote-debugging of a machine over a serial link. */
3176 start_remote (int from_tty
)
3178 inferior
*inf
= current_inferior ();
3179 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3181 /* Always go on waiting for the target, regardless of the mode. */
3182 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3183 indicate to wait_for_inferior that a target should timeout if
3184 nothing is returned (instead of just blocking). Because of this,
3185 targets expecting an immediate response need to, internally, set
3186 things up so that the target_wait() is forced to eventually
3188 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3189 differentiate to its caller what the state of the target is after
3190 the initial open has been performed. Here we're assuming that
3191 the target has stopped. It should be possible to eventually have
3192 target_open() return to the caller an indication that the target
3193 is currently running and GDB state should be set to the same as
3194 for an async run. */
3195 wait_for_inferior (inf
);
3197 /* Now that the inferior has stopped, do any bookkeeping like
3198 loading shared libraries. We want to do this before normal_stop,
3199 so that the displayed frame is up to date. */
3200 post_create_inferior (current_top_target (), from_tty
);
3205 /* Initialize static vars when a new inferior begins. */
3208 init_wait_for_inferior (void)
3210 /* These are meaningless until the first time through wait_for_inferior. */
3212 breakpoint_init_inferior (inf_starting
);
3214 clear_proceed_status (0);
3216 nullify_last_target_wait_ptid ();
3218 previous_inferior_ptid
= inferior_ptid
;
3223 static void handle_inferior_event (struct execution_control_state
*ecs
);
3225 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3226 struct execution_control_state
*ecs
);
3227 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3228 struct execution_control_state
*ecs
);
3229 static void handle_signal_stop (struct execution_control_state
*ecs
);
3230 static void check_exception_resume (struct execution_control_state
*,
3231 struct frame_info
*);
3233 static void end_stepping_range (struct execution_control_state
*ecs
);
3234 static void stop_waiting (struct execution_control_state
*ecs
);
3235 static void keep_going (struct execution_control_state
*ecs
);
3236 static void process_event_stop_test (struct execution_control_state
*ecs
);
3237 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3239 /* This function is attached as a "thread_stop_requested" observer.
3240 Cleanup local state that assumed the PTID was to be resumed, and
3241 report the stop to the frontend. */
3244 infrun_thread_stop_requested (ptid_t ptid
)
3246 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3248 /* PTID was requested to stop. If the thread was already stopped,
3249 but the user/frontend doesn't know about that yet (e.g., the
3250 thread had been temporarily paused for some step-over), set up
3251 for reporting the stop now. */
3252 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3254 if (tp
->state
!= THREAD_RUNNING
)
3259 /* Remove matching threads from the step-over queue, so
3260 start_step_over doesn't try to resume them
3262 if (thread_is_in_step_over_chain (tp
))
3263 global_thread_step_over_chain_remove (tp
);
3265 /* If the thread is stopped, but the user/frontend doesn't
3266 know about that yet, queue a pending event, as if the
3267 thread had just stopped now. Unless the thread already had
3269 if (!tp
->suspend
.waitstatus_pending_p
)
3271 tp
->suspend
.waitstatus_pending_p
= 1;
3272 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3273 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3276 /* Clear the inline-frame state, since we're re-processing the
3278 clear_inline_frame_state (tp
);
3280 /* If this thread was paused because some other thread was
3281 doing an inline-step over, let that finish first. Once
3282 that happens, we'll restart all threads and consume pending
3283 stop events then. */
3284 if (step_over_info_valid_p ())
3287 /* Otherwise we can process the (new) pending event now. Set
3288 it so this pending event is considered by
3295 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3297 if (target_last_proc_target
== tp
->inf
->process_target ()
3298 && target_last_wait_ptid
== tp
->ptid
)
3299 nullify_last_target_wait_ptid ();
3302 /* Delete the step resume, single-step and longjmp/exception resume
3303 breakpoints of TP. */
3306 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3308 delete_step_resume_breakpoint (tp
);
3309 delete_exception_resume_breakpoint (tp
);
3310 delete_single_step_breakpoints (tp
);
3313 /* If the target still has execution, call FUNC for each thread that
3314 just stopped. In all-stop, that's all the non-exited threads; in
3315 non-stop, that's the current thread, only. */
3317 typedef void (*for_each_just_stopped_thread_callback_func
)
3318 (struct thread_info
*tp
);
3321 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3323 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3326 if (target_is_non_stop_p ())
3328 /* If in non-stop mode, only the current thread stopped. */
3329 func (inferior_thread ());
3333 /* In all-stop mode, all threads have stopped. */
3334 for (thread_info
*tp
: all_non_exited_threads ())
3339 /* Delete the step resume and longjmp/exception resume breakpoints of
3340 the threads that just stopped. */
3343 delete_just_stopped_threads_infrun_breakpoints (void)
3345 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3348 /* Delete the single-step breakpoints of the threads that just
3352 delete_just_stopped_threads_single_step_breakpoints (void)
3354 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3360 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3361 const struct target_waitstatus
*ws
)
3363 std::string status_string
= target_waitstatus_to_string (ws
);
3366 /* The text is split over several lines because it was getting too long.
3367 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3368 output as a unit; we want only one timestamp printed if debug_timestamp
3371 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3374 waiton_ptid
.tid ());
3375 if (waiton_ptid
.pid () != -1)
3376 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3377 stb
.printf (", status) =\n");
3378 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3382 target_pid_to_str (result_ptid
).c_str ());
3383 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3385 /* This uses %s in part to handle %'s in the text, but also to avoid
3386 a gcc error: the format attribute requires a string literal. */
3387 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3390 /* Select a thread at random, out of those which are resumed and have
3393 static struct thread_info
*
3394 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3398 auto has_event
= [&] (thread_info
*tp
)
3400 return (tp
->ptid
.matches (waiton_ptid
)
3402 && tp
->suspend
.waitstatus_pending_p
);
3405 /* First see how many events we have. Count only resumed threads
3406 that have an event pending. */
3407 for (thread_info
*tp
: inf
->non_exited_threads ())
3411 if (num_events
== 0)
3414 /* Now randomly pick a thread out of those that have had events. */
3415 int random_selector
= (int) ((num_events
* (double) rand ())
3416 / (RAND_MAX
+ 1.0));
3419 infrun_log_debug ("Found %d events, selecting #%d",
3420 num_events
, random_selector
);
3422 /* Select the Nth thread that has had an event. */
3423 for (thread_info
*tp
: inf
->non_exited_threads ())
3425 if (random_selector
-- == 0)
3428 gdb_assert_not_reached ("event thread not found");
3431 /* Wrapper for target_wait that first checks whether threads have
3432 pending statuses to report before actually asking the target for
3433 more events. INF is the inferior we're using to call target_wait
3437 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3438 target_waitstatus
*status
, int options
)
3441 struct thread_info
*tp
;
3443 /* We know that we are looking for an event in the target of inferior
3444 INF, but we don't know which thread the event might come from. As
3445 such we want to make sure that INFERIOR_PTID is reset so that none of
3446 the wait code relies on it - doing so is always a mistake. */
3447 switch_to_inferior_no_thread (inf
);
3449 /* First check if there is a resumed thread with a wait status
3451 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3453 tp
= random_pending_event_thread (inf
, ptid
);
3457 infrun_log_debug ("Waiting for specific thread %s.",
3458 target_pid_to_str (ptid
).c_str ());
3460 /* We have a specific thread to check. */
3461 tp
= find_thread_ptid (inf
, ptid
);
3462 gdb_assert (tp
!= NULL
);
3463 if (!tp
->suspend
.waitstatus_pending_p
)
3468 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3469 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3471 struct regcache
*regcache
= get_thread_regcache (tp
);
3472 struct gdbarch
*gdbarch
= regcache
->arch ();
3476 pc
= regcache_read_pc (regcache
);
3478 if (pc
!= tp
->suspend
.stop_pc
)
3480 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3481 target_pid_to_str (tp
->ptid
).c_str (),
3482 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3483 paddress (gdbarch
, pc
));
3486 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3488 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3489 target_pid_to_str (tp
->ptid
).c_str (),
3490 paddress (gdbarch
, pc
));
3497 infrun_log_debug ("pending event of %s cancelled.",
3498 target_pid_to_str (tp
->ptid
).c_str ());
3500 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3501 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3507 infrun_log_debug ("Using pending wait status %s for %s.",
3508 target_waitstatus_to_string
3509 (&tp
->suspend
.waitstatus
).c_str (),
3510 target_pid_to_str (tp
->ptid
).c_str ());
3512 /* Now that we've selected our final event LWP, un-adjust its PC
3513 if it was a software breakpoint (and the target doesn't
3514 always adjust the PC itself). */
3515 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3516 && !target_supports_stopped_by_sw_breakpoint ())
3518 struct regcache
*regcache
;
3519 struct gdbarch
*gdbarch
;
3522 regcache
= get_thread_regcache (tp
);
3523 gdbarch
= regcache
->arch ();
3525 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3530 pc
= regcache_read_pc (regcache
);
3531 regcache_write_pc (regcache
, pc
+ decr_pc
);
3535 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3536 *status
= tp
->suspend
.waitstatus
;
3537 tp
->suspend
.waitstatus_pending_p
= 0;
3539 /* Wake up the event loop again, until all pending events are
3541 if (target_is_async_p ())
3542 mark_async_event_handler (infrun_async_inferior_event_token
);
3546 /* But if we don't find one, we'll have to wait. */
3548 if (deprecated_target_wait_hook
)
3549 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3551 event_ptid
= target_wait (ptid
, status
, options
);
3556 /* Returns true if INF has any resumed thread with a status
3560 threads_are_resumed_pending_p (inferior
*inf
)
3562 for (thread_info
*tp
: inf
->non_exited_threads ())
3564 && tp
->suspend
.waitstatus_pending_p
)
3570 /* Wrapper for target_wait that first checks whether threads have
3571 pending statuses to report before actually asking the target for
3572 more events. Polls for events from all inferiors/targets. */
3575 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3577 int num_inferiors
= 0;
3578 int random_selector
;
3580 /* For fairness, we pick the first inferior/target to poll at
3581 random, and then continue polling the rest of the inferior list
3582 starting from that one in a circular fashion until the whole list
3585 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3587 return (inf
->process_target () != NULL
3588 && (threads_are_executing (inf
->process_target ())
3589 || threads_are_resumed_pending_p (inf
))
3590 && ptid_t (inf
->pid
).matches (wait_ptid
));
3593 /* First see how many resumed inferiors we have. */
3594 for (inferior
*inf
: all_inferiors ())
3595 if (inferior_matches (inf
))
3598 if (num_inferiors
== 0)
3600 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3604 /* Now randomly pick an inferior out of those that were resumed. */
3605 random_selector
= (int)
3606 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3608 if (num_inferiors
> 1)
3609 infrun_log_debug ("Found %d inferiors, starting at #%d",
3610 num_inferiors
, random_selector
);
3612 /* Select the Nth inferior that was resumed. */
3614 inferior
*selected
= nullptr;
3616 for (inferior
*inf
: all_inferiors ())
3617 if (inferior_matches (inf
))
3618 if (random_selector
-- == 0)
3624 /* Now poll for events out of each of the resumed inferior's
3625 targets, starting from the selected one. */
3627 auto do_wait
= [&] (inferior
*inf
)
3629 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3630 ecs
->target
= inf
->process_target ();
3631 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3634 /* Needed in all-stop+target-non-stop mode, because we end up here
3635 spuriously after the target is all stopped and we've already
3636 reported the stop to the user, polling for events. */
3637 scoped_restore_current_thread restore_thread
;
3639 int inf_num
= selected
->num
;
3640 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3641 if (inferior_matches (inf
))
3645 for (inferior
*inf
= inferior_list
;
3646 inf
!= NULL
&& inf
->num
< inf_num
;
3648 if (inferior_matches (inf
))
3652 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3656 /* Prepare and stabilize the inferior for detaching it. E.g.,
3657 detaching while a thread is displaced stepping is a recipe for
3658 crashing it, as nothing would readjust the PC out of the scratch
3662 prepare_for_detach (void)
3664 struct inferior
*inf
= current_inferior ();
3665 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3667 // displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3669 /* Is any thread of this process displaced stepping? If not,
3670 there's nothing else to do. */
3671 if (displaced_step_in_progress (inf
))
3674 infrun_log_debug ("displaced-stepping in-process while detaching");
3676 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3681 struct execution_control_state ecss
;
3682 struct execution_control_state
*ecs
;
3685 memset (ecs
, 0, sizeof (*ecs
));
3687 overlay_cache_invalid
= 1;
3688 /* Flush target cache before starting to handle each event.
3689 Target was running and cache could be stale. This is just a
3690 heuristic. Running threads may modify target memory, but we
3691 don't get any event. */
3692 target_dcache_invalidate ();
3694 do_target_wait (pid_ptid
, ecs
, 0);
3697 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3699 /* If an error happens while handling the event, propagate GDB's
3700 knowledge of the executing state to the frontend/user running
3702 scoped_finish_thread_state
finish_state (inf
->process_target (),
3705 /* Now figure out what to do with the result of the result. */
3706 handle_inferior_event (ecs
);
3708 /* No error, don't finish the state yet. */
3709 finish_state
.release ();
3711 /* Breakpoints and watchpoints are not installed on the target
3712 at this point, and signals are passed directly to the
3713 inferior, so this must mean the process is gone. */
3714 if (!ecs
->wait_some_more
)
3716 restore_detaching
.release ();
3717 error (_("Program exited while detaching"));
3721 restore_detaching
.release ();
3724 /* Wait for control to return from inferior to debugger.
3726 If inferior gets a signal, we may decide to start it up again
3727 instead of returning. That is why there is a loop in this function.
3728 When this function actually returns it means the inferior
3729 should be left stopped and GDB should read more commands. */
3732 wait_for_inferior (inferior
*inf
)
3734 infrun_log_debug ("wait_for_inferior ()");
3736 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3738 /* If an error happens while handling the event, propagate GDB's
3739 knowledge of the executing state to the frontend/user running
3741 scoped_finish_thread_state finish_state
3742 (inf
->process_target (), minus_one_ptid
);
3746 struct execution_control_state ecss
;
3747 struct execution_control_state
*ecs
= &ecss
;
3749 memset (ecs
, 0, sizeof (*ecs
));
3751 overlay_cache_invalid
= 1;
3753 /* Flush target cache before starting to handle each event.
3754 Target was running and cache could be stale. This is just a
3755 heuristic. Running threads may modify target memory, but we
3756 don't get any event. */
3757 target_dcache_invalidate ();
3759 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3760 ecs
->target
= inf
->process_target ();
3763 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3765 /* Now figure out what to do with the result of the result. */
3766 handle_inferior_event (ecs
);
3768 if (!ecs
->wait_some_more
)
3772 /* No error, don't finish the state yet. */
3773 finish_state
.release ();
3776 /* Cleanup that reinstalls the readline callback handler, if the
3777 target is running in the background. If while handling the target
3778 event something triggered a secondary prompt, like e.g., a
3779 pagination prompt, we'll have removed the callback handler (see
3780 gdb_readline_wrapper_line). Need to do this as we go back to the
3781 event loop, ready to process further input. Note this has no
3782 effect if the handler hasn't actually been removed, because calling
3783 rl_callback_handler_install resets the line buffer, thus losing
3787 reinstall_readline_callback_handler_cleanup ()
3789 struct ui
*ui
= current_ui
;
3793 /* We're not going back to the top level event loop yet. Don't
3794 install the readline callback, as it'd prep the terminal,
3795 readline-style (raw, noecho) (e.g., --batch). We'll install
3796 it the next time the prompt is displayed, when we're ready
3801 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3802 gdb_rl_callback_handler_reinstall ();
3805 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3806 that's just the event thread. In all-stop, that's all threads. */
3809 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3811 if (ecs
->event_thread
!= NULL
3812 && ecs
->event_thread
->thread_fsm
!= NULL
)
3813 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3817 for (thread_info
*thr
: all_non_exited_threads ())
3819 if (thr
->thread_fsm
== NULL
)
3821 if (thr
== ecs
->event_thread
)
3824 switch_to_thread (thr
);
3825 thr
->thread_fsm
->clean_up (thr
);
3828 if (ecs
->event_thread
!= NULL
)
3829 switch_to_thread (ecs
->event_thread
);
3833 /* Helper for all_uis_check_sync_execution_done that works on the
3837 check_curr_ui_sync_execution_done (void)
3839 struct ui
*ui
= current_ui
;
3841 if (ui
->prompt_state
== PROMPT_NEEDED
3843 && !gdb_in_secondary_prompt_p (ui
))
3845 target_terminal::ours ();
3846 gdb::observers::sync_execution_done
.notify ();
3847 ui_register_input_event_handler (ui
);
3854 all_uis_check_sync_execution_done (void)
3856 SWITCH_THRU_ALL_UIS ()
3858 check_curr_ui_sync_execution_done ();
3865 all_uis_on_sync_execution_starting (void)
3867 SWITCH_THRU_ALL_UIS ()
3869 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3870 async_disable_stdin ();
3874 /* Asynchronous version of wait_for_inferior. It is called by the
3875 event loop whenever a change of state is detected on the file
3876 descriptor corresponding to the target. It can be called more than
3877 once to complete a single execution command. In such cases we need
3878 to keep the state in a global variable ECSS. If it is the last time
3879 that this function is called for a single execution command, then
3880 report to the user that the inferior has stopped, and do the
3881 necessary cleanups. */
3884 fetch_inferior_event (void *client_data
)
3886 struct execution_control_state ecss
;
3887 struct execution_control_state
*ecs
= &ecss
;
3890 memset (ecs
, 0, sizeof (*ecs
));
3892 /* Events are always processed with the main UI as current UI. This
3893 way, warnings, debug output, etc. are always consistently sent to
3894 the main console. */
3895 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3897 /* End up with readline processing input, if necessary. */
3899 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3901 /* We're handling a live event, so make sure we're doing live
3902 debugging. If we're looking at traceframes while the target is
3903 running, we're going to need to get back to that mode after
3904 handling the event. */
3905 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3908 maybe_restore_traceframe
.emplace ();
3909 set_current_traceframe (-1);
3912 /* The user/frontend should not notice a thread switch due to
3913 internal events. Make sure we revert to the user selected
3914 thread and frame after handling the event and running any
3915 breakpoint commands. */
3916 scoped_restore_current_thread restore_thread
;
3918 overlay_cache_invalid
= 1;
3919 /* Flush target cache before starting to handle each event. Target
3920 was running and cache could be stale. This is just a heuristic.
3921 Running threads may modify target memory, but we don't get any
3923 target_dcache_invalidate ();
3925 scoped_restore save_exec_dir
3926 = make_scoped_restore (&execution_direction
,
3927 target_execution_direction ());
3929 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3932 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3934 /* Switch to the target that generated the event, so we can do
3935 target calls. Any inferior bound to the target will do, so we
3936 just switch to the first we find. */
3937 for (inferior
*inf
: all_inferiors (ecs
->target
))
3939 switch_to_inferior_no_thread (inf
);
3944 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3946 /* If an error happens while handling the event, propagate GDB's
3947 knowledge of the executing state to the frontend/user running
3949 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3950 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3952 /* Get executed before scoped_restore_current_thread above to apply
3953 still for the thread which has thrown the exception. */
3954 auto defer_bpstat_clear
3955 = make_scope_exit (bpstat_clear_actions
);
3956 auto defer_delete_threads
3957 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3959 /* Now figure out what to do with the result of the result. */
3960 handle_inferior_event (ecs
);
3962 if (!ecs
->wait_some_more
)
3964 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3965 int should_stop
= 1;
3966 struct thread_info
*thr
= ecs
->event_thread
;
3968 delete_just_stopped_threads_infrun_breakpoints ();
3972 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3974 if (thread_fsm
!= NULL
)
3975 should_stop
= thread_fsm
->should_stop (thr
);
3984 bool should_notify_stop
= true;
3987 clean_up_just_stopped_threads_fsms (ecs
);
3989 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3990 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3992 if (should_notify_stop
)
3994 /* We may not find an inferior if this was a process exit. */
3995 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3996 proceeded
= normal_stop ();
4001 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4005 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4006 previously selected thread is gone. We have two
4007 choices - switch to no thread selected, or restore the
4008 previously selected thread (now exited). We chose the
4009 later, just because that's what GDB used to do. After
4010 this, "info threads" says "The current thread <Thread
4011 ID 2> has terminated." instead of "No thread
4015 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4016 restore_thread
.dont_restore ();
4020 defer_delete_threads
.release ();
4021 defer_bpstat_clear
.release ();
4023 /* No error, don't finish the thread states yet. */
4024 finish_state
.release ();
4026 /* This scope is used to ensure that readline callbacks are
4027 reinstalled here. */
4030 /* If a UI was in sync execution mode, and now isn't, restore its
4031 prompt (a synchronous execution command has finished, and we're
4032 ready for input). */
4033 all_uis_check_sync_execution_done ();
4036 && exec_done_display_p
4037 && (inferior_ptid
== null_ptid
4038 || inferior_thread ()->state
!= THREAD_RUNNING
))
4039 printf_unfiltered (_("completed.\n"));
4045 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4046 struct symtab_and_line sal
)
4048 /* This can be removed once this function no longer implicitly relies on the
4049 inferior_ptid value. */
4050 gdb_assert (inferior_ptid
== tp
->ptid
);
4052 tp
->control
.step_frame_id
= get_frame_id (frame
);
4053 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4055 tp
->current_symtab
= sal
.symtab
;
4056 tp
->current_line
= sal
.line
;
4059 /* Clear context switchable stepping state. */
4062 init_thread_stepping_state (struct thread_info
*tss
)
4064 tss
->stepped_breakpoint
= 0;
4065 tss
->stepping_over_breakpoint
= 0;
4066 tss
->stepping_over_watchpoint
= 0;
4067 tss
->step_after_step_resume_breakpoint
= 0;
4073 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4074 target_waitstatus status
)
4076 target_last_proc_target
= target
;
4077 target_last_wait_ptid
= ptid
;
4078 target_last_waitstatus
= status
;
4084 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4085 target_waitstatus
*status
)
4087 if (target
!= nullptr)
4088 *target
= target_last_proc_target
;
4089 if (ptid
!= nullptr)
4090 *ptid
= target_last_wait_ptid
;
4091 if (status
!= nullptr)
4092 *status
= target_last_waitstatus
;
4098 nullify_last_target_wait_ptid (void)
4100 target_last_proc_target
= nullptr;
4101 target_last_wait_ptid
= minus_one_ptid
;
4102 target_last_waitstatus
= {};
4105 /* Switch thread contexts. */
4108 context_switch (execution_control_state
*ecs
)
4110 if (ecs
->ptid
!= inferior_ptid
4111 && (inferior_ptid
== null_ptid
4112 || ecs
->event_thread
!= inferior_thread ()))
4114 infrun_log_debug ("Switching context from %s to %s",
4115 target_pid_to_str (inferior_ptid
).c_str (),
4116 target_pid_to_str (ecs
->ptid
).c_str ());
4119 switch_to_thread (ecs
->event_thread
);
4122 /* If the target can't tell whether we've hit breakpoints
4123 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4124 check whether that could have been caused by a breakpoint. If so,
4125 adjust the PC, per gdbarch_decr_pc_after_break. */
4128 adjust_pc_after_break (struct thread_info
*thread
,
4129 struct target_waitstatus
*ws
)
4131 struct regcache
*regcache
;
4132 struct gdbarch
*gdbarch
;
4133 CORE_ADDR breakpoint_pc
, decr_pc
;
4135 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4136 we aren't, just return.
4138 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4139 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4140 implemented by software breakpoints should be handled through the normal
4143 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4144 different signals (SIGILL or SIGEMT for instance), but it is less
4145 clear where the PC is pointing afterwards. It may not match
4146 gdbarch_decr_pc_after_break. I don't know any specific target that
4147 generates these signals at breakpoints (the code has been in GDB since at
4148 least 1992) so I can not guess how to handle them here.
4150 In earlier versions of GDB, a target with
4151 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4152 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4153 target with both of these set in GDB history, and it seems unlikely to be
4154 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4156 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4159 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4162 /* In reverse execution, when a breakpoint is hit, the instruction
4163 under it has already been de-executed. The reported PC always
4164 points at the breakpoint address, so adjusting it further would
4165 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4168 B1 0x08000000 : INSN1
4169 B2 0x08000001 : INSN2
4171 PC -> 0x08000003 : INSN4
4173 Say you're stopped at 0x08000003 as above. Reverse continuing
4174 from that point should hit B2 as below. Reading the PC when the
4175 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4176 been de-executed already.
4178 B1 0x08000000 : INSN1
4179 B2 PC -> 0x08000001 : INSN2
4183 We can't apply the same logic as for forward execution, because
4184 we would wrongly adjust the PC to 0x08000000, since there's a
4185 breakpoint at PC - 1. We'd then report a hit on B1, although
4186 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4188 if (execution_direction
== EXEC_REVERSE
)
4191 /* If the target can tell whether the thread hit a SW breakpoint,
4192 trust it. Targets that can tell also adjust the PC
4194 if (target_supports_stopped_by_sw_breakpoint ())
4197 /* Note that relying on whether a breakpoint is planted in memory to
4198 determine this can fail. E.g,. the breakpoint could have been
4199 removed since. Or the thread could have been told to step an
4200 instruction the size of a breakpoint instruction, and only
4201 _after_ was a breakpoint inserted at its address. */
4203 /* If this target does not decrement the PC after breakpoints, then
4204 we have nothing to do. */
4205 regcache
= get_thread_regcache (thread
);
4206 gdbarch
= regcache
->arch ();
4208 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4212 const address_space
*aspace
= regcache
->aspace ();
4214 /* Find the location where (if we've hit a breakpoint) the
4215 breakpoint would be. */
4216 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4218 /* If the target can't tell whether a software breakpoint triggered,
4219 fallback to figuring it out based on breakpoints we think were
4220 inserted in the target, and on whether the thread was stepped or
4223 /* Check whether there actually is a software breakpoint inserted at
4226 If in non-stop mode, a race condition is possible where we've
4227 removed a breakpoint, but stop events for that breakpoint were
4228 already queued and arrive later. To suppress those spurious
4229 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4230 and retire them after a number of stop events are reported. Note
4231 this is an heuristic and can thus get confused. The real fix is
4232 to get the "stopped by SW BP and needs adjustment" info out of
4233 the target/kernel (and thus never reach here; see above). */
4234 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4235 || (target_is_non_stop_p ()
4236 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4238 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4240 if (record_full_is_used ())
4241 restore_operation_disable
.emplace
4242 (record_full_gdb_operation_disable_set ());
4244 /* When using hardware single-step, a SIGTRAP is reported for both
4245 a completed single-step and a software breakpoint. Need to
4246 differentiate between the two, as the latter needs adjusting
4247 but the former does not.
4249 The SIGTRAP can be due to a completed hardware single-step only if
4250 - we didn't insert software single-step breakpoints
4251 - this thread is currently being stepped
4253 If any of these events did not occur, we must have stopped due
4254 to hitting a software breakpoint, and have to back up to the
4257 As a special case, we could have hardware single-stepped a
4258 software breakpoint. In this case (prev_pc == breakpoint_pc),
4259 we also need to back up to the breakpoint address. */
4261 if (thread_has_single_step_breakpoints_set (thread
)
4262 || !currently_stepping (thread
)
4263 || (thread
->stepped_breakpoint
4264 && thread
->prev_pc
== breakpoint_pc
))
4265 regcache_write_pc (regcache
, breakpoint_pc
);
4270 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4272 for (frame
= get_prev_frame (frame
);
4274 frame
= get_prev_frame (frame
))
4276 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4278 if (get_frame_type (frame
) != INLINE_FRAME
)
4285 /* Look for an inline frame that is marked for skip.
4286 If PREV_FRAME is TRUE start at the previous frame,
4287 otherwise start at the current frame. Stop at the
4288 first non-inline frame, or at the frame where the
4292 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4294 struct frame_info
*frame
= get_current_frame ();
4297 frame
= get_prev_frame (frame
);
4299 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4301 const char *fn
= NULL
;
4302 symtab_and_line sal
;
4305 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4307 if (get_frame_type (frame
) != INLINE_FRAME
)
4310 sal
= find_frame_sal (frame
);
4311 sym
= get_frame_function (frame
);
4314 fn
= sym
->print_name ();
4317 && function_name_is_marked_for_skip (fn
, sal
))
4324 /* If the event thread has the stop requested flag set, pretend it
4325 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4329 handle_stop_requested (struct execution_control_state
*ecs
)
4331 if (ecs
->event_thread
->stop_requested
)
4333 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4334 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4335 handle_signal_stop (ecs
);
4341 /* Auxiliary function that handles syscall entry/return events.
4342 It returns 1 if the inferior should keep going (and GDB
4343 should ignore the event), or 0 if the event deserves to be
4347 handle_syscall_event (struct execution_control_state
*ecs
)
4349 struct regcache
*regcache
;
4352 context_switch (ecs
);
4354 regcache
= get_thread_regcache (ecs
->event_thread
);
4355 syscall_number
= ecs
->ws
.value
.syscall_number
;
4356 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4358 if (catch_syscall_enabled () > 0
4359 && catching_syscall_number (syscall_number
) > 0)
4361 infrun_log_debug ("syscall number=%d", syscall_number
);
4363 ecs
->event_thread
->control
.stop_bpstat
4364 = bpstat_stop_status (regcache
->aspace (),
4365 ecs
->event_thread
->suspend
.stop_pc
,
4366 ecs
->event_thread
, &ecs
->ws
);
4368 if (handle_stop_requested (ecs
))
4371 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4373 /* Catchpoint hit. */
4378 if (handle_stop_requested (ecs
))
4381 /* If no catchpoint triggered for this, then keep going. */
4386 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4389 fill_in_stop_func (struct gdbarch
*gdbarch
,
4390 struct execution_control_state
*ecs
)
4392 if (!ecs
->stop_func_filled_in
)
4396 /* Don't care about return value; stop_func_start and stop_func_name
4397 will both be 0 if it doesn't work. */
4398 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4399 &ecs
->stop_func_name
,
4400 &ecs
->stop_func_start
,
4401 &ecs
->stop_func_end
,
4404 /* The call to find_pc_partial_function, above, will set
4405 stop_func_start and stop_func_end to the start and end
4406 of the range containing the stop pc. If this range
4407 contains the entry pc for the block (which is always the
4408 case for contiguous blocks), advance stop_func_start past
4409 the function's start offset and entrypoint. Note that
4410 stop_func_start is NOT advanced when in a range of a
4411 non-contiguous block that does not contain the entry pc. */
4412 if (block
!= nullptr
4413 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4414 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4416 ecs
->stop_func_start
4417 += gdbarch_deprecated_function_start_offset (gdbarch
);
4419 if (gdbarch_skip_entrypoint_p (gdbarch
))
4420 ecs
->stop_func_start
4421 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4424 ecs
->stop_func_filled_in
= 1;
4429 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4431 static enum stop_kind
4432 get_inferior_stop_soon (execution_control_state
*ecs
)
4434 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4436 gdb_assert (inf
!= NULL
);
4437 return inf
->control
.stop_soon
;
4440 /* Poll for one event out of the current target. Store the resulting
4441 waitstatus in WS, and return the event ptid. Does not block. */
4444 poll_one_curr_target (struct target_waitstatus
*ws
)
4448 overlay_cache_invalid
= 1;
4450 /* Flush target cache before starting to handle each event.
4451 Target was running and cache could be stale. This is just a
4452 heuristic. Running threads may modify target memory, but we
4453 don't get any event. */
4454 target_dcache_invalidate ();
4456 if (deprecated_target_wait_hook
)
4457 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4459 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4462 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4467 /* An event reported by wait_one. */
4469 struct wait_one_event
4471 /* The target the event came out of. */
4472 process_stratum_target
*target
;
4474 /* The PTID the event was for. */
4477 /* The waitstatus. */
4478 target_waitstatus ws
;
4481 /* Wait for one event out of any target. */
4483 static wait_one_event
4488 for (inferior
*inf
: all_inferiors ())
4490 process_stratum_target
*target
= inf
->process_target ();
4492 || !target
->is_async_p ()
4493 || !target
->threads_executing
)
4496 switch_to_inferior_no_thread (inf
);
4498 wait_one_event event
;
4499 event
.target
= target
;
4500 event
.ptid
= poll_one_curr_target (&event
.ws
);
4502 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4504 /* If nothing is resumed, remove the target from the
4508 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4512 /* Block waiting for some event. */
4519 for (inferior
*inf
: all_inferiors ())
4521 process_stratum_target
*target
= inf
->process_target ();
4523 || !target
->is_async_p ()
4524 || !target
->threads_executing
)
4527 int fd
= target
->async_wait_fd ();
4528 FD_SET (fd
, &readfds
);
4535 /* No waitable targets left. All must be stopped. */
4536 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4541 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4547 perror_with_name ("interruptible_select");
4552 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4553 instead of the current thread. */
4554 #define THREAD_STOPPED_BY(REASON) \
4556 thread_stopped_by_ ## REASON (ptid_t ptid) \
4558 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4559 inferior_ptid = ptid; \
4561 return target_stopped_by_ ## REASON (); \
4564 /* Generate thread_stopped_by_watchpoint. */
4565 THREAD_STOPPED_BY (watchpoint
)
4566 /* Generate thread_stopped_by_sw_breakpoint. */
4567 THREAD_STOPPED_BY (sw_breakpoint
)
4568 /* Generate thread_stopped_by_hw_breakpoint. */
4569 THREAD_STOPPED_BY (hw_breakpoint
)
4571 /* Save the thread's event and stop reason to process it later. */
4574 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4576 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4577 target_waitstatus_to_string (ws
).c_str (),
4582 /* Record for later. */
4583 tp
->suspend
.waitstatus
= *ws
;
4584 tp
->suspend
.waitstatus_pending_p
= 1;
4586 struct regcache
*regcache
= get_thread_regcache (tp
);
4587 const address_space
*aspace
= regcache
->aspace ();
4589 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4590 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4592 CORE_ADDR pc
= regcache_read_pc (regcache
);
4594 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4596 if (thread_stopped_by_watchpoint (tp
->ptid
))
4598 tp
->suspend
.stop_reason
4599 = TARGET_STOPPED_BY_WATCHPOINT
;
4601 else if (target_supports_stopped_by_sw_breakpoint ()
4602 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4604 tp
->suspend
.stop_reason
4605 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4607 else if (target_supports_stopped_by_hw_breakpoint ()
4608 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4610 tp
->suspend
.stop_reason
4611 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4613 else if (!target_supports_stopped_by_hw_breakpoint ()
4614 && hardware_breakpoint_inserted_here_p (aspace
,
4617 tp
->suspend
.stop_reason
4618 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4620 else if (!target_supports_stopped_by_sw_breakpoint ()
4621 && software_breakpoint_inserted_here_p (aspace
,
4624 tp
->suspend
.stop_reason
4625 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4627 else if (!thread_has_single_step_breakpoints_set (tp
)
4628 && currently_stepping (tp
))
4630 tp
->suspend
.stop_reason
4631 = TARGET_STOPPED_BY_SINGLE_STEP
;
4636 /* Mark the non-executing threads accordingly. In all-stop, all
4637 threads of all processes are stopped when we get any event
4638 reported. In non-stop mode, only the event thread stops. */
4641 mark_non_executing_threads (process_stratum_target
*target
,
4643 struct target_waitstatus ws
)
4647 if (!target_is_non_stop_p ())
4648 mark_ptid
= minus_one_ptid
;
4649 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4650 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4652 /* If we're handling a process exit in non-stop mode, even
4653 though threads haven't been deleted yet, one would think
4654 that there is nothing to do, as threads of the dead process
4655 will be soon deleted, and threads of any other process were
4656 left running. However, on some targets, threads survive a
4657 process exit event. E.g., for the "checkpoint" command,
4658 when the current checkpoint/fork exits, linux-fork.c
4659 automatically switches to another fork from within
4660 target_mourn_inferior, by associating the same
4661 inferior/thread to another fork. We haven't mourned yet at
4662 this point, but we must mark any threads left in the
4663 process as not-executing so that finish_thread_state marks
4664 them stopped (in the user's perspective) if/when we present
4665 the stop to the user. */
4666 mark_ptid
= ptid_t (event_ptid
.pid ());
4669 mark_ptid
= event_ptid
;
4671 set_executing (target
, mark_ptid
, false);
4673 /* Likewise the resumed flag. */
4674 set_resumed (target
, mark_ptid
, false);
4680 stop_all_threads (void)
4682 /* We may need multiple passes to discover all threads. */
4686 gdb_assert (exists_non_stop_target ());
4688 infrun_log_debug ("stop_all_threads");
4690 scoped_restore_current_thread restore_thread
;
4692 /* Enable thread events of all targets. */
4693 for (auto *target
: all_non_exited_process_targets ())
4695 switch_to_target_no_thread (target
);
4696 target_thread_events (true);
4701 /* Disable thread events of all targets. */
4702 for (auto *target
: all_non_exited_process_targets ())
4704 switch_to_target_no_thread (target
);
4705 target_thread_events (false);
4709 infrun_log_debug ("stop_all_threads done");
4712 /* Request threads to stop, and then wait for the stops. Because
4713 threads we already know about can spawn more threads while we're
4714 trying to stop them, and we only learn about new threads when we
4715 update the thread list, do this in a loop, and keep iterating
4716 until two passes find no threads that need to be stopped. */
4717 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4719 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4723 int waits_needed
= 0;
4725 for (auto *target
: all_non_exited_process_targets ())
4727 switch_to_target_no_thread (target
);
4728 update_thread_list ();
4731 /* Go through all threads looking for threads that we need
4732 to tell the target to stop. */
4733 for (thread_info
*t
: all_non_exited_threads ())
4735 /* For a single-target setting with an all-stop target,
4736 we would not even arrive here. For a multi-target
4737 setting, until GDB is able to handle a mixture of
4738 all-stop and non-stop targets, simply skip all-stop
4739 targets' threads. This should be fine due to the
4740 protection of 'check_multi_target_resumption'. */
4742 switch_to_thread_no_regs (t
);
4743 if (!target_is_non_stop_p ())
4748 /* If already stopping, don't request a stop again.
4749 We just haven't seen the notification yet. */
4750 if (!t
->stop_requested
)
4752 infrun_log_debug (" %s executing, need stop",
4753 target_pid_to_str (t
->ptid
).c_str ());
4754 target_stop (t
->ptid
);
4755 t
->stop_requested
= 1;
4759 infrun_log_debug (" %s executing, already stopping",
4760 target_pid_to_str (t
->ptid
).c_str ());
4763 if (t
->stop_requested
)
4768 infrun_log_debug (" %s not executing",
4769 target_pid_to_str (t
->ptid
).c_str ());
4771 /* The thread may be not executing, but still be
4772 resumed with a pending status to process. */
4777 if (waits_needed
== 0)
4780 /* If we find new threads on the second iteration, restart
4781 over. We want to see two iterations in a row with all
4786 for (int i
= 0; i
< waits_needed
; i
++)
4788 wait_one_event event
= wait_one ();
4790 infrun_log_debug ("%s %s\n",
4791 target_waitstatus_to_string (&event
.ws
).c_str (),
4792 target_pid_to_str (event
.ptid
).c_str ());
4794 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4796 /* All resumed threads exited. */
4799 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4800 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4801 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4803 /* One thread/process exited/signalled. */
4805 thread_info
*t
= nullptr;
4807 /* The target may have reported just a pid. If so, try
4808 the first non-exited thread. */
4809 if (event
.ptid
.is_pid ())
4811 int pid
= event
.ptid
.pid ();
4812 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4813 for (thread_info
*tp
: inf
->non_exited_threads ())
4819 /* If there is no available thread, the event would
4820 have to be appended to a per-inferior event list,
4821 which does not exist (and if it did, we'd have
4822 to adjust run control command to be able to
4823 resume such an inferior). We assert here instead
4824 of going into an infinite loop. */
4825 gdb_assert (t
!= nullptr);
4827 infrun_log_debug ("using %s\n",
4828 target_pid_to_str (t
->ptid
).c_str ());
4832 t
= find_thread_ptid (event
.target
, event
.ptid
);
4833 /* Check if this is the first time we see this thread.
4834 Don't bother adding if it individually exited. */
4836 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4837 t
= add_thread (event
.target
, event
.ptid
);
4842 /* Set the threads as non-executing to avoid
4843 another stop attempt on them. */
4844 switch_to_thread_no_regs (t
);
4845 mark_non_executing_threads (event
.target
, event
.ptid
,
4847 save_waitstatus (t
, &event
.ws
);
4848 t
->stop_requested
= false;
4853 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4855 t
= add_thread (event
.target
, event
.ptid
);
4857 t
->stop_requested
= 0;
4860 t
->control
.may_range_step
= 0;
4862 /* This may be the first time we see the inferior report
4864 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4865 if (inf
->needs_setup
)
4867 switch_to_thread_no_regs (t
);
4871 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4872 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4874 /* We caught the event that we intended to catch, so
4875 there's no event pending. */
4876 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4877 t
->suspend
.waitstatus_pending_p
= 0;
4879 if (displaced_step_finish (t
, GDB_SIGNAL_0
) < 0)
4881 /* Add it back to the step-over queue. */
4882 infrun_log_debug ("displaced-step of %s "
4883 "canceled: adding back to the "
4884 "step-over queue\n",
4885 target_pid_to_str (t
->ptid
).c_str ());
4887 t
->control
.trap_expected
= 0;
4888 global_thread_step_over_chain_enqueue (t
);
4893 enum gdb_signal sig
;
4894 struct regcache
*regcache
;
4898 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4900 infrun_log_debug ("target_wait %s, saving "
4901 "status for %d.%ld.%ld\n",
4908 /* Record for later. */
4909 save_waitstatus (t
, &event
.ws
);
4911 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4912 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4914 if (displaced_step_finish (t
, sig
) < 0)
4916 /* Add it back to the step-over queue. */
4917 t
->control
.trap_expected
= 0;
4918 global_thread_step_over_chain_enqueue (t
);
4921 regcache
= get_thread_regcache (t
);
4922 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4924 infrun_log_debug ("saved stop_pc=%s for %s "
4925 "(currently_stepping=%d)\n",
4926 paddress (target_gdbarch (),
4927 t
->suspend
.stop_pc
),
4928 target_pid_to_str (t
->ptid
).c_str (),
4929 currently_stepping (t
));
4937 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4940 handle_no_resumed (struct execution_control_state
*ecs
)
4942 if (target_can_async_p ())
4946 for (ui
*ui
: all_uis ())
4948 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4956 /* There were no unwaited-for children left in the target, but,
4957 we're not synchronously waiting for events either. Just
4960 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4961 prepare_to_wait (ecs
);
4966 /* Otherwise, if we were running a synchronous execution command, we
4967 may need to cancel it and give the user back the terminal.
4969 In non-stop mode, the target can't tell whether we've already
4970 consumed previous stop events, so it can end up sending us a
4971 no-resumed event like so:
4973 #0 - thread 1 is left stopped
4975 #1 - thread 2 is resumed and hits breakpoint
4976 -> TARGET_WAITKIND_STOPPED
4978 #2 - thread 3 is resumed and exits
4979 this is the last resumed thread, so
4980 -> TARGET_WAITKIND_NO_RESUMED
4982 #3 - gdb processes stop for thread 2 and decides to re-resume
4985 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4986 thread 2 is now resumed, so the event should be ignored.
4988 IOW, if the stop for thread 2 doesn't end a foreground command,
4989 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4990 event. But it could be that the event meant that thread 2 itself
4991 (or whatever other thread was the last resumed thread) exited.
4993 To address this we refresh the thread list and check whether we
4994 have resumed threads _now_. In the example above, this removes
4995 thread 3 from the thread list. If thread 2 was re-resumed, we
4996 ignore this event. If we find no thread resumed, then we cancel
4997 the synchronous command show "no unwaited-for " to the user. */
4998 update_thread_list ();
5000 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
5002 if (thread
->executing
5003 || thread
->suspend
.waitstatus_pending_p
)
5005 /* There were no unwaited-for children left in the target at
5006 some point, but there are now. Just ignore. */
5007 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
5008 "(ignoring: found resumed)");
5009 prepare_to_wait (ecs
);
5014 /* Go ahead and report the event. */
5018 /* Given an execution control state that has been freshly filled in by
5019 an event from the inferior, figure out what it means and take
5022 The alternatives are:
5024 1) stop_waiting and return; to really stop and return to the
5027 2) keep_going and return; to wait for the next event (set
5028 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5032 handle_inferior_event (struct execution_control_state
*ecs
)
5034 /* Make sure that all temporary struct value objects that were
5035 created during the handling of the event get deleted at the
5037 scoped_value_mark free_values
;
5039 enum stop_kind stop_soon
;
5041 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5043 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5045 /* We had an event in the inferior, but we are not interested in
5046 handling it at this level. The lower layers have already
5047 done what needs to be done, if anything.
5049 One of the possible circumstances for this is when the
5050 inferior produces output for the console. The inferior has
5051 not stopped, and we are ignoring the event. Another possible
5052 circumstance is any event which the lower level knows will be
5053 reported multiple times without an intervening resume. */
5054 prepare_to_wait (ecs
);
5058 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5060 prepare_to_wait (ecs
);
5064 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5065 && handle_no_resumed (ecs
))
5068 /* Cache the last target/ptid/waitstatus. */
5069 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5071 /* Always clear state belonging to the previous time we stopped. */
5072 stop_stack_dummy
= STOP_NONE
;
5074 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5076 /* No unwaited-for children left. IOW, all resumed children
5078 stop_print_frame
= 0;
5083 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5084 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5086 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5087 /* If it's a new thread, add it to the thread database. */
5088 if (ecs
->event_thread
== NULL
)
5089 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5091 /* Disable range stepping. If the next step request could use a
5092 range, this will be end up re-enabled then. */
5093 ecs
->event_thread
->control
.may_range_step
= 0;
5096 /* Dependent on valid ECS->EVENT_THREAD. */
5097 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5099 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5100 reinit_frame_cache ();
5102 breakpoint_retire_moribund ();
5104 /* First, distinguish signals caused by the debugger from signals
5105 that have to do with the program's own actions. Note that
5106 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5107 on the operating system version. Here we detect when a SIGILL or
5108 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5109 something similar for SIGSEGV, since a SIGSEGV will be generated
5110 when we're trying to execute a breakpoint instruction on a
5111 non-executable stack. This happens for call dummy breakpoints
5112 for architectures like SPARC that place call dummies on the
5114 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5115 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5116 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5117 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5119 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5121 if (breakpoint_inserted_here_p (regcache
->aspace (),
5122 regcache_read_pc (regcache
)))
5124 infrun_log_debug ("Treating signal as SIGTRAP");
5125 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5129 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5131 switch (ecs
->ws
.kind
)
5133 case TARGET_WAITKIND_LOADED
:
5134 context_switch (ecs
);
5135 /* Ignore gracefully during startup of the inferior, as it might
5136 be the shell which has just loaded some objects, otherwise
5137 add the symbols for the newly loaded objects. Also ignore at
5138 the beginning of an attach or remote session; we will query
5139 the full list of libraries once the connection is
5142 stop_soon
= get_inferior_stop_soon (ecs
);
5143 if (stop_soon
== NO_STOP_QUIETLY
)
5145 struct regcache
*regcache
;
5147 regcache
= get_thread_regcache (ecs
->event_thread
);
5149 handle_solib_event ();
5151 ecs
->event_thread
->control
.stop_bpstat
5152 = bpstat_stop_status (regcache
->aspace (),
5153 ecs
->event_thread
->suspend
.stop_pc
,
5154 ecs
->event_thread
, &ecs
->ws
);
5156 if (handle_stop_requested (ecs
))
5159 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5161 /* A catchpoint triggered. */
5162 process_event_stop_test (ecs
);
5166 /* If requested, stop when the dynamic linker notifies
5167 gdb of events. This allows the user to get control
5168 and place breakpoints in initializer routines for
5169 dynamically loaded objects (among other things). */
5170 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5171 if (stop_on_solib_events
)
5173 /* Make sure we print "Stopped due to solib-event" in
5175 stop_print_frame
= 1;
5182 /* If we are skipping through a shell, or through shared library
5183 loading that we aren't interested in, resume the program. If
5184 we're running the program normally, also resume. */
5185 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5187 /* Loading of shared libraries might have changed breakpoint
5188 addresses. Make sure new breakpoints are inserted. */
5189 if (stop_soon
== NO_STOP_QUIETLY
)
5190 insert_breakpoints ();
5191 resume (GDB_SIGNAL_0
);
5192 prepare_to_wait (ecs
);
5196 /* But stop if we're attaching or setting up a remote
5198 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5199 || stop_soon
== STOP_QUIETLY_REMOTE
)
5201 infrun_log_debug ("quietly stopped");
5206 internal_error (__FILE__
, __LINE__
,
5207 _("unhandled stop_soon: %d"), (int) stop_soon
);
5209 case TARGET_WAITKIND_SPURIOUS
:
5210 if (handle_stop_requested (ecs
))
5212 context_switch (ecs
);
5213 resume (GDB_SIGNAL_0
);
5214 prepare_to_wait (ecs
);
5217 case TARGET_WAITKIND_THREAD_CREATED
:
5218 if (handle_stop_requested (ecs
))
5220 context_switch (ecs
);
5221 if (!switch_back_to_stepped_thread (ecs
))
5225 case TARGET_WAITKIND_EXITED
:
5226 case TARGET_WAITKIND_SIGNALLED
:
5227 inferior_ptid
= ecs
->ptid
;
5228 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5229 set_current_program_space (current_inferior ()->pspace
);
5230 handle_vfork_child_exec_or_exit (0);
5231 target_terminal::ours (); /* Must do this before mourn anyway. */
5233 /* Clearing any previous state of convenience variables. */
5234 clear_exit_convenience_vars ();
5236 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5238 /* Record the exit code in the convenience variable $_exitcode, so
5239 that the user can inspect this again later. */
5240 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5241 (LONGEST
) ecs
->ws
.value
.integer
);
5243 /* Also record this in the inferior itself. */
5244 current_inferior ()->has_exit_code
= 1;
5245 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5247 /* Support the --return-child-result option. */
5248 return_child_result_value
= ecs
->ws
.value
.integer
;
5250 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5254 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5256 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5258 /* Set the value of the internal variable $_exitsignal,
5259 which holds the signal uncaught by the inferior. */
5260 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5261 gdbarch_gdb_signal_to_target (gdbarch
,
5262 ecs
->ws
.value
.sig
));
5266 /* We don't have access to the target's method used for
5267 converting between signal numbers (GDB's internal
5268 representation <-> target's representation).
5269 Therefore, we cannot do a good job at displaying this
5270 information to the user. It's better to just warn
5271 her about it (if infrun debugging is enabled), and
5273 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5277 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5280 gdb_flush (gdb_stdout
);
5281 target_mourn_inferior (inferior_ptid
);
5282 stop_print_frame
= 0;
5286 case TARGET_WAITKIND_FORKED
:
5287 case TARGET_WAITKIND_VFORKED
:
5288 /* Check whether the inferior is displaced stepping. */
5290 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5291 struct gdbarch
*gdbarch
= regcache
->arch ();
5293 /* If checking displaced stepping is supported, and thread
5294 ecs->ptid is displaced stepping. */
5295 if (displaced_step_in_progress (ecs
->event_thread
))
5297 struct inferior
*parent_inf
5298 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5299 struct regcache
*child_regcache
;
5300 CORE_ADDR parent_pc
;
5302 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5304 // struct displaced_step_inferior_state *displaced
5305 // = get_displaced_stepping_state (parent_inf);
5307 /* Restore scratch pad for child process. */
5308 //displaced_step_restore (displaced, ecs->ws.value.related_pid);
5309 // FIXME: we should restore all the buffers that were currently in use
5312 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5313 indicating that the displaced stepping of syscall instruction
5314 has been done. Perform cleanup for parent process here. Note
5315 that this operation also cleans up the child process for vfork,
5316 because their pages are shared. */
5317 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5318 /* Start a new step-over in another thread if there's one
5322 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5323 the child's PC is also within the scratchpad. Set the child's PC
5324 to the parent's PC value, which has already been fixed up.
5325 FIXME: we use the parent's aspace here, although we're touching
5326 the child, because the child hasn't been added to the inferior
5327 list yet at this point. */
5330 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5331 ecs
->ws
.value
.related_pid
,
5333 parent_inf
->aspace
);
5334 /* Read PC value of parent process. */
5335 parent_pc
= regcache_read_pc (regcache
);
5337 if (debug_displaced
)
5338 fprintf_unfiltered (gdb_stdlog
,
5339 "displaced: write child pc from %s to %s\n",
5341 regcache_read_pc (child_regcache
)),
5342 paddress (gdbarch
, parent_pc
));
5344 regcache_write_pc (child_regcache
, parent_pc
);
5348 context_switch (ecs
);
5350 /* Immediately detach breakpoints from the child before there's
5351 any chance of letting the user delete breakpoints from the
5352 breakpoint lists. If we don't do this early, it's easy to
5353 leave left over traps in the child, vis: "break foo; catch
5354 fork; c; <fork>; del; c; <child calls foo>". We only follow
5355 the fork on the last `continue', and by that time the
5356 breakpoint at "foo" is long gone from the breakpoint table.
5357 If we vforked, then we don't need to unpatch here, since both
5358 parent and child are sharing the same memory pages; we'll
5359 need to unpatch at follow/detach time instead to be certain
5360 that new breakpoints added between catchpoint hit time and
5361 vfork follow are detached. */
5362 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5364 /* This won't actually modify the breakpoint list, but will
5365 physically remove the breakpoints from the child. */
5366 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5369 delete_just_stopped_threads_single_step_breakpoints ();
5371 /* In case the event is caught by a catchpoint, remember that
5372 the event is to be followed at the next resume of the thread,
5373 and not immediately. */
5374 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5376 ecs
->event_thread
->suspend
.stop_pc
5377 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5379 ecs
->event_thread
->control
.stop_bpstat
5380 = bpstat_stop_status (get_current_regcache ()->aspace (),
5381 ecs
->event_thread
->suspend
.stop_pc
,
5382 ecs
->event_thread
, &ecs
->ws
);
5384 if (handle_stop_requested (ecs
))
5387 /* If no catchpoint triggered for this, then keep going. Note
5388 that we're interested in knowing the bpstat actually causes a
5389 stop, not just if it may explain the signal. Software
5390 watchpoints, for example, always appear in the bpstat. */
5391 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5394 = (follow_fork_mode_string
== follow_fork_mode_child
);
5396 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5398 process_stratum_target
*targ
5399 = ecs
->event_thread
->inf
->process_target ();
5401 bool should_resume
= follow_fork ();
5403 /* Note that one of these may be an invalid pointer,
5404 depending on detach_fork. */
5405 thread_info
*parent
= ecs
->event_thread
;
5407 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5409 /* At this point, the parent is marked running, and the
5410 child is marked stopped. */
5412 /* If not resuming the parent, mark it stopped. */
5413 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5414 parent
->set_running (false);
5416 /* If resuming the child, mark it running. */
5417 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5418 child
->set_running (true);
5420 /* In non-stop mode, also resume the other branch. */
5421 if (!detach_fork
&& (non_stop
5422 || (sched_multi
&& target_is_non_stop_p ())))
5425 switch_to_thread (parent
);
5427 switch_to_thread (child
);
5429 ecs
->event_thread
= inferior_thread ();
5430 ecs
->ptid
= inferior_ptid
;
5435 switch_to_thread (child
);
5437 switch_to_thread (parent
);
5439 ecs
->event_thread
= inferior_thread ();
5440 ecs
->ptid
= inferior_ptid
;
5448 process_event_stop_test (ecs
);
5451 case TARGET_WAITKIND_VFORK_DONE
:
5452 /* Done with the shared memory region. Re-insert breakpoints in
5453 the parent, and keep going. */
5455 context_switch (ecs
);
5457 current_inferior ()->waiting_for_vfork_done
= 0;
5458 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5460 if (handle_stop_requested (ecs
))
5463 /* This also takes care of reinserting breakpoints in the
5464 previously locked inferior. */
5468 case TARGET_WAITKIND_EXECD
:
5470 /* Note we can't read registers yet (the stop_pc), because we
5471 don't yet know the inferior's post-exec architecture.
5472 'stop_pc' is explicitly read below instead. */
5473 switch_to_thread_no_regs (ecs
->event_thread
);
5475 /* Do whatever is necessary to the parent branch of the vfork. */
5476 handle_vfork_child_exec_or_exit (1);
5478 /* This causes the eventpoints and symbol table to be reset.
5479 Must do this now, before trying to determine whether to
5481 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5483 /* In follow_exec we may have deleted the original thread and
5484 created a new one. Make sure that the event thread is the
5485 execd thread for that case (this is a nop otherwise). */
5486 ecs
->event_thread
= inferior_thread ();
5488 ecs
->event_thread
->suspend
.stop_pc
5489 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5491 ecs
->event_thread
->control
.stop_bpstat
5492 = bpstat_stop_status (get_current_regcache ()->aspace (),
5493 ecs
->event_thread
->suspend
.stop_pc
,
5494 ecs
->event_thread
, &ecs
->ws
);
5496 /* Note that this may be referenced from inside
5497 bpstat_stop_status above, through inferior_has_execd. */
5498 xfree (ecs
->ws
.value
.execd_pathname
);
5499 ecs
->ws
.value
.execd_pathname
= NULL
;
5501 if (handle_stop_requested (ecs
))
5504 /* If no catchpoint triggered for this, then keep going. */
5505 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5507 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5511 process_event_stop_test (ecs
);
5514 /* Be careful not to try to gather much state about a thread
5515 that's in a syscall. It's frequently a losing proposition. */
5516 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5517 /* Getting the current syscall number. */
5518 if (handle_syscall_event (ecs
) == 0)
5519 process_event_stop_test (ecs
);
5522 /* Before examining the threads further, step this thread to
5523 get it entirely out of the syscall. (We get notice of the
5524 event when the thread is just on the verge of exiting a
5525 syscall. Stepping one instruction seems to get it back
5527 case TARGET_WAITKIND_SYSCALL_RETURN
:
5528 if (handle_syscall_event (ecs
) == 0)
5529 process_event_stop_test (ecs
);
5532 case TARGET_WAITKIND_STOPPED
:
5533 handle_signal_stop (ecs
);
5536 case TARGET_WAITKIND_NO_HISTORY
:
5537 /* Reverse execution: target ran out of history info. */
5539 /* Switch to the stopped thread. */
5540 context_switch (ecs
);
5541 infrun_log_debug ("stopped");
5543 delete_just_stopped_threads_single_step_breakpoints ();
5544 ecs
->event_thread
->suspend
.stop_pc
5545 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5547 if (handle_stop_requested (ecs
))
5550 gdb::observers::no_history
.notify ();
5556 /* Restart threads back to what they were trying to do back when we
5557 paused them for an in-line step-over. The EVENT_THREAD thread is
5561 restart_threads (struct thread_info
*event_thread
)
5563 /* In case the instruction just stepped spawned a new thread. */
5564 update_thread_list ();
5566 for (thread_info
*tp
: all_non_exited_threads ())
5568 switch_to_thread_no_regs (tp
);
5570 if (tp
== event_thread
)
5572 infrun_log_debug ("restart threads: [%s] is event thread",
5573 target_pid_to_str (tp
->ptid
).c_str ());
5577 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5579 infrun_log_debug ("restart threads: [%s] not meant to be running",
5580 target_pid_to_str (tp
->ptid
).c_str ());
5586 infrun_log_debug ("restart threads: [%s] resumed",
5587 target_pid_to_str (tp
->ptid
).c_str ());
5588 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5592 if (thread_is_in_step_over_chain (tp
))
5594 infrun_log_debug ("restart threads: [%s] needs step-over",
5595 target_pid_to_str (tp
->ptid
).c_str ());
5596 gdb_assert (!tp
->resumed
);
5601 if (tp
->suspend
.waitstatus_pending_p
)
5603 infrun_log_debug ("restart threads: [%s] has pending status",
5604 target_pid_to_str (tp
->ptid
).c_str ());
5609 gdb_assert (!tp
->stop_requested
);
5611 /* If some thread needs to start a step-over at this point, it
5612 should still be in the step-over queue, and thus skipped
5614 if (thread_still_needs_step_over (tp
))
5616 internal_error (__FILE__
, __LINE__
,
5617 "thread [%s] needs a step-over, but not in "
5618 "step-over queue\n",
5619 target_pid_to_str (tp
->ptid
).c_str ());
5622 if (currently_stepping (tp
))
5624 infrun_log_debug ("restart threads: [%s] was stepping",
5625 target_pid_to_str (tp
->ptid
).c_str ());
5626 keep_going_stepped_thread (tp
);
5630 struct execution_control_state ecss
;
5631 struct execution_control_state
*ecs
= &ecss
;
5633 infrun_log_debug ("restart threads: [%s] continuing",
5634 target_pid_to_str (tp
->ptid
).c_str ());
5635 reset_ecs (ecs
, tp
);
5636 switch_to_thread (tp
);
5637 keep_going_pass_signal (ecs
);
5642 /* Callback for iterate_over_threads. Find a resumed thread that has
5643 a pending waitstatus. */
5646 resumed_thread_with_pending_status (struct thread_info
*tp
,
5650 && tp
->suspend
.waitstatus_pending_p
);
5653 /* Called when we get an event that may finish an in-line or
5654 out-of-line (displaced stepping) step-over started previously.
5655 Return true if the event is processed and we should go back to the
5656 event loop; false if the caller should continue processing the
5660 finish_step_over (struct execution_control_state
*ecs
)
5662 int had_step_over_info
;
5664 displaced_step_finish (ecs
->event_thread
,
5665 ecs
->event_thread
->suspend
.stop_signal
);
5667 had_step_over_info
= step_over_info_valid_p ();
5669 if (had_step_over_info
)
5671 /* If we're stepping over a breakpoint with all threads locked,
5672 then only the thread that was stepped should be reporting
5674 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5676 clear_step_over_info ();
5679 if (!target_is_non_stop_p ())
5682 /* Start a new step-over in another thread if there's one that
5686 /* If we were stepping over a breakpoint before, and haven't started
5687 a new in-line step-over sequence, then restart all other threads
5688 (except the event thread). We can't do this in all-stop, as then
5689 e.g., we wouldn't be able to issue any other remote packet until
5690 these other threads stop. */
5691 if (had_step_over_info
&& !step_over_info_valid_p ())
5693 struct thread_info
*pending
;
5695 /* If we only have threads with pending statuses, the restart
5696 below won't restart any thread and so nothing re-inserts the
5697 breakpoint we just stepped over. But we need it inserted
5698 when we later process the pending events, otherwise if
5699 another thread has a pending event for this breakpoint too,
5700 we'd discard its event (because the breakpoint that
5701 originally caused the event was no longer inserted). */
5702 context_switch (ecs
);
5703 insert_breakpoints ();
5705 restart_threads (ecs
->event_thread
);
5707 /* If we have events pending, go through handle_inferior_event
5708 again, picking up a pending event at random. This avoids
5709 thread starvation. */
5711 /* But not if we just stepped over a watchpoint in order to let
5712 the instruction execute so we can evaluate its expression.
5713 The set of watchpoints that triggered is recorded in the
5714 breakpoint objects themselves (see bp->watchpoint_triggered).
5715 If we processed another event first, that other event could
5716 clobber this info. */
5717 if (ecs
->event_thread
->stepping_over_watchpoint
)
5720 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5722 if (pending
!= NULL
)
5724 struct thread_info
*tp
= ecs
->event_thread
;
5725 struct regcache
*regcache
;
5727 infrun_log_debug ("found resumed threads with "
5728 "pending events, saving status");
5730 gdb_assert (pending
!= tp
);
5732 /* Record the event thread's event for later. */
5733 save_waitstatus (tp
, &ecs
->ws
);
5734 /* This was cleared early, by handle_inferior_event. Set it
5735 so this pending event is considered by
5739 gdb_assert (!tp
->executing
);
5741 regcache
= get_thread_regcache (tp
);
5742 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5744 infrun_log_debug ("saved stop_pc=%s for %s "
5745 "(currently_stepping=%d)\n",
5746 paddress (target_gdbarch (),
5747 tp
->suspend
.stop_pc
),
5748 target_pid_to_str (tp
->ptid
).c_str (),
5749 currently_stepping (tp
));
5751 /* This in-line step-over finished; clear this so we won't
5752 start a new one. This is what handle_signal_stop would
5753 do, if we returned false. */
5754 tp
->stepping_over_breakpoint
= 0;
5756 /* Wake up the event loop again. */
5757 mark_async_event_handler (infrun_async_inferior_event_token
);
5759 prepare_to_wait (ecs
);
5767 /* Come here when the program has stopped with a signal. */
5770 handle_signal_stop (struct execution_control_state
*ecs
)
5772 struct frame_info
*frame
;
5773 struct gdbarch
*gdbarch
;
5774 int stopped_by_watchpoint
;
5775 enum stop_kind stop_soon
;
5778 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5780 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5782 /* Do we need to clean up the state of a thread that has
5783 completed a displaced single-step? (Doing so usually affects
5784 the PC, so do it here, before we set stop_pc.) */
5785 if (finish_step_over (ecs
))
5788 /* If we either finished a single-step or hit a breakpoint, but
5789 the user wanted this thread to be stopped, pretend we got a
5790 SIG0 (generic unsignaled stop). */
5791 if (ecs
->event_thread
->stop_requested
5792 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5793 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5795 ecs
->event_thread
->suspend
.stop_pc
5796 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5800 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5801 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5803 switch_to_thread (ecs
->event_thread
);
5805 infrun_log_debug ("stop_pc=%s",
5806 paddress (reg_gdbarch
,
5807 ecs
->event_thread
->suspend
.stop_pc
));
5808 if (target_stopped_by_watchpoint ())
5812 infrun_log_debug ("stopped by watchpoint");
5814 if (target_stopped_data_address (current_top_target (), &addr
))
5815 infrun_log_debug ("stopped data address=%s",
5816 paddress (reg_gdbarch
, addr
));
5818 infrun_log_debug ("(no data address available)");
5822 /* This is originated from start_remote(), start_inferior() and
5823 shared libraries hook functions. */
5824 stop_soon
= get_inferior_stop_soon (ecs
);
5825 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5827 context_switch (ecs
);
5828 infrun_log_debug ("quietly stopped");
5829 stop_print_frame
= 1;
5834 /* This originates from attach_command(). We need to overwrite
5835 the stop_signal here, because some kernels don't ignore a
5836 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5837 See more comments in inferior.h. On the other hand, if we
5838 get a non-SIGSTOP, report it to the user - assume the backend
5839 will handle the SIGSTOP if it should show up later.
5841 Also consider that the attach is complete when we see a
5842 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5843 target extended-remote report it instead of a SIGSTOP
5844 (e.g. gdbserver). We already rely on SIGTRAP being our
5845 signal, so this is no exception.
5847 Also consider that the attach is complete when we see a
5848 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5849 the target to stop all threads of the inferior, in case the
5850 low level attach operation doesn't stop them implicitly. If
5851 they weren't stopped implicitly, then the stub will report a
5852 GDB_SIGNAL_0, meaning: stopped for no particular reason
5853 other than GDB's request. */
5854 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5855 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5856 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5857 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5859 stop_print_frame
= 1;
5861 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5865 /* See if something interesting happened to the non-current thread. If
5866 so, then switch to that thread. */
5867 if (ecs
->ptid
!= inferior_ptid
)
5869 infrun_log_debug ("context switch");
5871 context_switch (ecs
);
5873 if (deprecated_context_hook
)
5874 deprecated_context_hook (ecs
->event_thread
->global_num
);
5877 /* At this point, get hold of the now-current thread's frame. */
5878 frame
= get_current_frame ();
5879 gdbarch
= get_frame_arch (frame
);
5881 /* Pull the single step breakpoints out of the target. */
5882 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5884 struct regcache
*regcache
;
5887 regcache
= get_thread_regcache (ecs
->event_thread
);
5888 const address_space
*aspace
= regcache
->aspace ();
5890 pc
= regcache_read_pc (regcache
);
5892 /* However, before doing so, if this single-step breakpoint was
5893 actually for another thread, set this thread up for moving
5895 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5898 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5900 infrun_log_debug ("[%s] hit another thread's single-step "
5902 target_pid_to_str (ecs
->ptid
).c_str ());
5903 ecs
->hit_singlestep_breakpoint
= 1;
5908 infrun_log_debug ("[%s] hit its single-step breakpoint",
5909 target_pid_to_str (ecs
->ptid
).c_str ());
5912 delete_just_stopped_threads_single_step_breakpoints ();
5914 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5915 && ecs
->event_thread
->control
.trap_expected
5916 && ecs
->event_thread
->stepping_over_watchpoint
)
5917 stopped_by_watchpoint
= 0;
5919 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5921 /* If necessary, step over this watchpoint. We'll be back to display
5923 if (stopped_by_watchpoint
5924 && (target_have_steppable_watchpoint
5925 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5927 /* At this point, we are stopped at an instruction which has
5928 attempted to write to a piece of memory under control of
5929 a watchpoint. The instruction hasn't actually executed
5930 yet. If we were to evaluate the watchpoint expression
5931 now, we would get the old value, and therefore no change
5932 would seem to have occurred.
5934 In order to make watchpoints work `right', we really need
5935 to complete the memory write, and then evaluate the
5936 watchpoint expression. We do this by single-stepping the
5939 It may not be necessary to disable the watchpoint to step over
5940 it. For example, the PA can (with some kernel cooperation)
5941 single step over a watchpoint without disabling the watchpoint.
5943 It is far more common to need to disable a watchpoint to step
5944 the inferior over it. If we have non-steppable watchpoints,
5945 we must disable the current watchpoint; it's simplest to
5946 disable all watchpoints.
5948 Any breakpoint at PC must also be stepped over -- if there's
5949 one, it will have already triggered before the watchpoint
5950 triggered, and we either already reported it to the user, or
5951 it didn't cause a stop and we called keep_going. In either
5952 case, if there was a breakpoint at PC, we must be trying to
5954 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5959 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5960 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5961 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5962 ecs
->event_thread
->control
.stop_step
= 0;
5963 stop_print_frame
= 1;
5964 stopped_by_random_signal
= 0;
5965 bpstat stop_chain
= NULL
;
5967 /* Hide inlined functions starting here, unless we just performed stepi or
5968 nexti. After stepi and nexti, always show the innermost frame (not any
5969 inline function call sites). */
5970 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5972 const address_space
*aspace
5973 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5975 /* skip_inline_frames is expensive, so we avoid it if we can
5976 determine that the address is one where functions cannot have
5977 been inlined. This improves performance with inferiors that
5978 load a lot of shared libraries, because the solib event
5979 breakpoint is defined as the address of a function (i.e. not
5980 inline). Note that we have to check the previous PC as well
5981 as the current one to catch cases when we have just
5982 single-stepped off a breakpoint prior to reinstating it.
5983 Note that we're assuming that the code we single-step to is
5984 not inline, but that's not definitive: there's nothing
5985 preventing the event breakpoint function from containing
5986 inlined code, and the single-step ending up there. If the
5987 user had set a breakpoint on that inlined code, the missing
5988 skip_inline_frames call would break things. Fortunately
5989 that's an extremely unlikely scenario. */
5990 if (!pc_at_non_inline_function (aspace
,
5991 ecs
->event_thread
->suspend
.stop_pc
,
5993 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5994 && ecs
->event_thread
->control
.trap_expected
5995 && pc_at_non_inline_function (aspace
,
5996 ecs
->event_thread
->prev_pc
,
5999 stop_chain
= build_bpstat_chain (aspace
,
6000 ecs
->event_thread
->suspend
.stop_pc
,
6002 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6004 /* Re-fetch current thread's frame in case that invalidated
6006 frame
= get_current_frame ();
6007 gdbarch
= get_frame_arch (frame
);
6011 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6012 && ecs
->event_thread
->control
.trap_expected
6013 && gdbarch_single_step_through_delay_p (gdbarch
)
6014 && currently_stepping (ecs
->event_thread
))
6016 /* We're trying to step off a breakpoint. Turns out that we're
6017 also on an instruction that needs to be stepped multiple
6018 times before it's been fully executing. E.g., architectures
6019 with a delay slot. It needs to be stepped twice, once for
6020 the instruction and once for the delay slot. */
6021 int step_through_delay
6022 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6024 if (step_through_delay
)
6025 infrun_log_debug ("step through delay");
6027 if (ecs
->event_thread
->control
.step_range_end
== 0
6028 && step_through_delay
)
6030 /* The user issued a continue when stopped at a breakpoint.
6031 Set up for another trap and get out of here. */
6032 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6036 else if (step_through_delay
)
6038 /* The user issued a step when stopped at a breakpoint.
6039 Maybe we should stop, maybe we should not - the delay
6040 slot *might* correspond to a line of source. In any
6041 case, don't decide that here, just set
6042 ecs->stepping_over_breakpoint, making sure we
6043 single-step again before breakpoints are re-inserted. */
6044 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6048 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6049 handles this event. */
6050 ecs
->event_thread
->control
.stop_bpstat
6051 = bpstat_stop_status (get_current_regcache ()->aspace (),
6052 ecs
->event_thread
->suspend
.stop_pc
,
6053 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6055 /* Following in case break condition called a
6057 stop_print_frame
= 1;
6059 /* This is where we handle "moribund" watchpoints. Unlike
6060 software breakpoints traps, hardware watchpoint traps are
6061 always distinguishable from random traps. If no high-level
6062 watchpoint is associated with the reported stop data address
6063 anymore, then the bpstat does not explain the signal ---
6064 simply make sure to ignore it if `stopped_by_watchpoint' is
6067 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6068 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6070 && stopped_by_watchpoint
)
6072 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6076 /* NOTE: cagney/2003-03-29: These checks for a random signal
6077 at one stage in the past included checks for an inferior
6078 function call's call dummy's return breakpoint. The original
6079 comment, that went with the test, read:
6081 ``End of a stack dummy. Some systems (e.g. Sony news) give
6082 another signal besides SIGTRAP, so check here as well as
6085 If someone ever tries to get call dummys on a
6086 non-executable stack to work (where the target would stop
6087 with something like a SIGSEGV), then those tests might need
6088 to be re-instated. Given, however, that the tests were only
6089 enabled when momentary breakpoints were not being used, I
6090 suspect that it won't be the case.
6092 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6093 be necessary for call dummies on a non-executable stack on
6096 /* See if the breakpoints module can explain the signal. */
6098 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6099 ecs
->event_thread
->suspend
.stop_signal
);
6101 /* Maybe this was a trap for a software breakpoint that has since
6103 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6105 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6106 ecs
->event_thread
->suspend
.stop_pc
))
6108 struct regcache
*regcache
;
6111 /* Re-adjust PC to what the program would see if GDB was not
6113 regcache
= get_thread_regcache (ecs
->event_thread
);
6114 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6117 gdb::optional
<scoped_restore_tmpl
<int>>
6118 restore_operation_disable
;
6120 if (record_full_is_used ())
6121 restore_operation_disable
.emplace
6122 (record_full_gdb_operation_disable_set ());
6124 regcache_write_pc (regcache
,
6125 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6130 /* A delayed software breakpoint event. Ignore the trap. */
6131 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6136 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6137 has since been removed. */
6138 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6140 /* A delayed hardware breakpoint event. Ignore the trap. */
6141 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6146 /* If not, perhaps stepping/nexting can. */
6148 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6149 && currently_stepping (ecs
->event_thread
));
6151 /* Perhaps the thread hit a single-step breakpoint of _another_
6152 thread. Single-step breakpoints are transparent to the
6153 breakpoints module. */
6155 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6157 /* No? Perhaps we got a moribund watchpoint. */
6159 random_signal
= !stopped_by_watchpoint
;
6161 /* Always stop if the user explicitly requested this thread to
6163 if (ecs
->event_thread
->stop_requested
)
6166 infrun_log_debug ("user-requested stop");
6169 /* For the program's own signals, act according to
6170 the signal handling tables. */
6174 /* Signal not for debugging purposes. */
6175 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6176 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6178 infrun_log_debug ("random signal (%s)",
6179 gdb_signal_to_symbol_string (stop_signal
));
6181 stopped_by_random_signal
= 1;
6183 /* Always stop on signals if we're either just gaining control
6184 of the program, or the user explicitly requested this thread
6185 to remain stopped. */
6186 if (stop_soon
!= NO_STOP_QUIETLY
6187 || ecs
->event_thread
->stop_requested
6189 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6195 /* Notify observers the signal has "handle print" set. Note we
6196 returned early above if stopping; normal_stop handles the
6197 printing in that case. */
6198 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6200 /* The signal table tells us to print about this signal. */
6201 target_terminal::ours_for_output ();
6202 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6203 target_terminal::inferior ();
6206 /* Clear the signal if it should not be passed. */
6207 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6208 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6210 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6211 && ecs
->event_thread
->control
.trap_expected
6212 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6214 /* We were just starting a new sequence, attempting to
6215 single-step off of a breakpoint and expecting a SIGTRAP.
6216 Instead this signal arrives. This signal will take us out
6217 of the stepping range so GDB needs to remember to, when
6218 the signal handler returns, resume stepping off that
6220 /* To simplify things, "continue" is forced to use the same
6221 code paths as single-step - set a breakpoint at the
6222 signal return address and then, once hit, step off that
6224 infrun_log_debug ("signal arrived while stepping over breakpoint");
6226 insert_hp_step_resume_breakpoint_at_frame (frame
);
6227 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6228 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6229 ecs
->event_thread
->control
.trap_expected
= 0;
6231 /* If we were nexting/stepping some other thread, switch to
6232 it, so that we don't continue it, losing control. */
6233 if (!switch_back_to_stepped_thread (ecs
))
6238 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6239 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6241 || ecs
->event_thread
->control
.step_range_end
== 1)
6242 && frame_id_eq (get_stack_frame_id (frame
),
6243 ecs
->event_thread
->control
.step_stack_frame_id
)
6244 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6246 /* The inferior is about to take a signal that will take it
6247 out of the single step range. Set a breakpoint at the
6248 current PC (which is presumably where the signal handler
6249 will eventually return) and then allow the inferior to
6252 Note that this is only needed for a signal delivered
6253 while in the single-step range. Nested signals aren't a
6254 problem as they eventually all return. */
6255 infrun_log_debug ("signal may take us out of single-step range");
6257 clear_step_over_info ();
6258 insert_hp_step_resume_breakpoint_at_frame (frame
);
6259 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6260 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6261 ecs
->event_thread
->control
.trap_expected
= 0;
6266 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6267 when either there's a nested signal, or when there's a
6268 pending signal enabled just as the signal handler returns
6269 (leaving the inferior at the step-resume-breakpoint without
6270 actually executing it). Either way continue until the
6271 breakpoint is really hit. */
6273 if (!switch_back_to_stepped_thread (ecs
))
6275 infrun_log_debug ("random signal, keep going");
6282 process_event_stop_test (ecs
);
6285 /* Come here when we've got some debug event / signal we can explain
6286 (IOW, not a random signal), and test whether it should cause a
6287 stop, or whether we should resume the inferior (transparently).
6288 E.g., could be a breakpoint whose condition evaluates false; we
6289 could be still stepping within the line; etc. */
6292 process_event_stop_test (struct execution_control_state
*ecs
)
6294 struct symtab_and_line stop_pc_sal
;
6295 struct frame_info
*frame
;
6296 struct gdbarch
*gdbarch
;
6297 CORE_ADDR jmp_buf_pc
;
6298 struct bpstat_what what
;
6300 /* Handle cases caused by hitting a breakpoint. */
6302 frame
= get_current_frame ();
6303 gdbarch
= get_frame_arch (frame
);
6305 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6307 if (what
.call_dummy
)
6309 stop_stack_dummy
= what
.call_dummy
;
6312 /* A few breakpoint types have callbacks associated (e.g.,
6313 bp_jit_event). Run them now. */
6314 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6316 /* If we hit an internal event that triggers symbol changes, the
6317 current frame will be invalidated within bpstat_what (e.g., if we
6318 hit an internal solib event). Re-fetch it. */
6319 frame
= get_current_frame ();
6320 gdbarch
= get_frame_arch (frame
);
6322 switch (what
.main_action
)
6324 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6325 /* If we hit the breakpoint at longjmp while stepping, we
6326 install a momentary breakpoint at the target of the
6329 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6331 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6333 if (what
.is_longjmp
)
6335 struct value
*arg_value
;
6337 /* If we set the longjmp breakpoint via a SystemTap probe,
6338 then use it to extract the arguments. The destination PC
6339 is the third argument to the probe. */
6340 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6343 jmp_buf_pc
= value_as_address (arg_value
);
6344 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6346 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6347 || !gdbarch_get_longjmp_target (gdbarch
,
6348 frame
, &jmp_buf_pc
))
6350 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6351 "(!gdbarch_get_longjmp_target)");
6356 /* Insert a breakpoint at resume address. */
6357 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6360 check_exception_resume (ecs
, frame
);
6364 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6366 struct frame_info
*init_frame
;
6368 /* There are several cases to consider.
6370 1. The initiating frame no longer exists. In this case we
6371 must stop, because the exception or longjmp has gone too
6374 2. The initiating frame exists, and is the same as the
6375 current frame. We stop, because the exception or longjmp
6378 3. The initiating frame exists and is different from the
6379 current frame. This means the exception or longjmp has
6380 been caught beneath the initiating frame, so keep going.
6382 4. longjmp breakpoint has been placed just to protect
6383 against stale dummy frames and user is not interested in
6384 stopping around longjmps. */
6386 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6388 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6390 delete_exception_resume_breakpoint (ecs
->event_thread
);
6392 if (what
.is_longjmp
)
6394 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6396 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6404 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6408 struct frame_id current_id
6409 = get_frame_id (get_current_frame ());
6410 if (frame_id_eq (current_id
,
6411 ecs
->event_thread
->initiating_frame
))
6413 /* Case 2. Fall through. */
6423 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6425 delete_step_resume_breakpoint (ecs
->event_thread
);
6427 end_stepping_range (ecs
);
6431 case BPSTAT_WHAT_SINGLE
:
6432 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6433 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6434 /* Still need to check other stuff, at least the case where we
6435 are stepping and step out of the right range. */
6438 case BPSTAT_WHAT_STEP_RESUME
:
6439 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6441 delete_step_resume_breakpoint (ecs
->event_thread
);
6442 if (ecs
->event_thread
->control
.proceed_to_finish
6443 && execution_direction
== EXEC_REVERSE
)
6445 struct thread_info
*tp
= ecs
->event_thread
;
6447 /* We are finishing a function in reverse, and just hit the
6448 step-resume breakpoint at the start address of the
6449 function, and we're almost there -- just need to back up
6450 by one more single-step, which should take us back to the
6452 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6456 fill_in_stop_func (gdbarch
, ecs
);
6457 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6458 && execution_direction
== EXEC_REVERSE
)
6460 /* We are stepping over a function call in reverse, and just
6461 hit the step-resume breakpoint at the start address of
6462 the function. Go back to single-stepping, which should
6463 take us back to the function call. */
6464 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6470 case BPSTAT_WHAT_STOP_NOISY
:
6471 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6472 stop_print_frame
= 1;
6474 /* Assume the thread stopped for a breapoint. We'll still check
6475 whether a/the breakpoint is there when the thread is next
6477 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6482 case BPSTAT_WHAT_STOP_SILENT
:
6483 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6484 stop_print_frame
= 0;
6486 /* Assume the thread stopped for a breapoint. We'll still check
6487 whether a/the breakpoint is there when the thread is next
6489 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6493 case BPSTAT_WHAT_HP_STEP_RESUME
:
6494 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6496 delete_step_resume_breakpoint (ecs
->event_thread
);
6497 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6499 /* Back when the step-resume breakpoint was inserted, we
6500 were trying to single-step off a breakpoint. Go back to
6502 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6503 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6509 case BPSTAT_WHAT_KEEP_CHECKING
:
6513 /* If we stepped a permanent breakpoint and we had a high priority
6514 step-resume breakpoint for the address we stepped, but we didn't
6515 hit it, then we must have stepped into the signal handler. The
6516 step-resume was only necessary to catch the case of _not_
6517 stepping into the handler, so delete it, and fall through to
6518 checking whether the step finished. */
6519 if (ecs
->event_thread
->stepped_breakpoint
)
6521 struct breakpoint
*sr_bp
6522 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6525 && sr_bp
->loc
->permanent
6526 && sr_bp
->type
== bp_hp_step_resume
6527 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6529 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6530 delete_step_resume_breakpoint (ecs
->event_thread
);
6531 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6535 /* We come here if we hit a breakpoint but should not stop for it.
6536 Possibly we also were stepping and should stop for that. So fall
6537 through and test for stepping. But, if not stepping, do not
6540 /* In all-stop mode, if we're currently stepping but have stopped in
6541 some other thread, we need to switch back to the stepped thread. */
6542 if (switch_back_to_stepped_thread (ecs
))
6545 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6547 infrun_log_debug ("step-resume breakpoint is inserted");
6549 /* Having a step-resume breakpoint overrides anything
6550 else having to do with stepping commands until
6551 that breakpoint is reached. */
6556 if (ecs
->event_thread
->control
.step_range_end
== 0)
6558 infrun_log_debug ("no stepping, continue");
6559 /* Likewise if we aren't even stepping. */
6564 /* Re-fetch current thread's frame in case the code above caused
6565 the frame cache to be re-initialized, making our FRAME variable
6566 a dangling pointer. */
6567 frame
= get_current_frame ();
6568 gdbarch
= get_frame_arch (frame
);
6569 fill_in_stop_func (gdbarch
, ecs
);
6571 /* If stepping through a line, keep going if still within it.
6573 Note that step_range_end is the address of the first instruction
6574 beyond the step range, and NOT the address of the last instruction
6577 Note also that during reverse execution, we may be stepping
6578 through a function epilogue and therefore must detect when
6579 the current-frame changes in the middle of a line. */
6581 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6583 && (execution_direction
!= EXEC_REVERSE
6584 || frame_id_eq (get_frame_id (frame
),
6585 ecs
->event_thread
->control
.step_frame_id
)))
6588 ("stepping inside range [%s-%s]",
6589 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6590 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6592 /* Tentatively re-enable range stepping; `resume' disables it if
6593 necessary (e.g., if we're stepping over a breakpoint or we
6594 have software watchpoints). */
6595 ecs
->event_thread
->control
.may_range_step
= 1;
6597 /* When stepping backward, stop at beginning of line range
6598 (unless it's the function entry point, in which case
6599 keep going back to the call point). */
6600 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6601 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6602 && stop_pc
!= ecs
->stop_func_start
6603 && execution_direction
== EXEC_REVERSE
)
6604 end_stepping_range (ecs
);
6611 /* We stepped out of the stepping range. */
6613 /* If we are stepping at the source level and entered the runtime
6614 loader dynamic symbol resolution code...
6616 EXEC_FORWARD: we keep on single stepping until we exit the run
6617 time loader code and reach the callee's address.
6619 EXEC_REVERSE: we've already executed the callee (backward), and
6620 the runtime loader code is handled just like any other
6621 undebuggable function call. Now we need only keep stepping
6622 backward through the trampoline code, and that's handled further
6623 down, so there is nothing for us to do here. */
6625 if (execution_direction
!= EXEC_REVERSE
6626 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6627 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6629 CORE_ADDR pc_after_resolver
=
6630 gdbarch_skip_solib_resolver (gdbarch
,
6631 ecs
->event_thread
->suspend
.stop_pc
);
6633 infrun_log_debug ("stepped into dynsym resolve code");
6635 if (pc_after_resolver
)
6637 /* Set up a step-resume breakpoint at the address
6638 indicated by SKIP_SOLIB_RESOLVER. */
6639 symtab_and_line sr_sal
;
6640 sr_sal
.pc
= pc_after_resolver
;
6641 sr_sal
.pspace
= get_frame_program_space (frame
);
6643 insert_step_resume_breakpoint_at_sal (gdbarch
,
6644 sr_sal
, null_frame_id
);
6651 /* Step through an indirect branch thunk. */
6652 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6653 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6654 ecs
->event_thread
->suspend
.stop_pc
))
6656 infrun_log_debug ("stepped into indirect branch thunk");
6661 if (ecs
->event_thread
->control
.step_range_end
!= 1
6662 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6663 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6664 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6666 infrun_log_debug ("stepped into signal trampoline");
6667 /* The inferior, while doing a "step" or "next", has ended up in
6668 a signal trampoline (either by a signal being delivered or by
6669 the signal handler returning). Just single-step until the
6670 inferior leaves the trampoline (either by calling the handler
6676 /* If we're in the return path from a shared library trampoline,
6677 we want to proceed through the trampoline when stepping. */
6678 /* macro/2012-04-25: This needs to come before the subroutine
6679 call check below as on some targets return trampolines look
6680 like subroutine calls (MIPS16 return thunks). */
6681 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6682 ecs
->event_thread
->suspend
.stop_pc
,
6683 ecs
->stop_func_name
)
6684 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6686 /* Determine where this trampoline returns. */
6687 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6688 CORE_ADDR real_stop_pc
6689 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6691 infrun_log_debug ("stepped into solib return tramp");
6693 /* Only proceed through if we know where it's going. */
6696 /* And put the step-breakpoint there and go until there. */
6697 symtab_and_line sr_sal
;
6698 sr_sal
.pc
= real_stop_pc
;
6699 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6700 sr_sal
.pspace
= get_frame_program_space (frame
);
6702 /* Do not specify what the fp should be when we stop since
6703 on some machines the prologue is where the new fp value
6705 insert_step_resume_breakpoint_at_sal (gdbarch
,
6706 sr_sal
, null_frame_id
);
6708 /* Restart without fiddling with the step ranges or
6715 /* Check for subroutine calls. The check for the current frame
6716 equalling the step ID is not necessary - the check of the
6717 previous frame's ID is sufficient - but it is a common case and
6718 cheaper than checking the previous frame's ID.
6720 NOTE: frame_id_eq will never report two invalid frame IDs as
6721 being equal, so to get into this block, both the current and
6722 previous frame must have valid frame IDs. */
6723 /* The outer_frame_id check is a heuristic to detect stepping
6724 through startup code. If we step over an instruction which
6725 sets the stack pointer from an invalid value to a valid value,
6726 we may detect that as a subroutine call from the mythical
6727 "outermost" function. This could be fixed by marking
6728 outermost frames as !stack_p,code_p,special_p. Then the
6729 initial outermost frame, before sp was valid, would
6730 have code_addr == &_start. See the comment in frame_id_eq
6732 if (!frame_id_eq (get_stack_frame_id (frame
),
6733 ecs
->event_thread
->control
.step_stack_frame_id
)
6734 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6735 ecs
->event_thread
->control
.step_stack_frame_id
)
6736 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6738 || (ecs
->event_thread
->control
.step_start_function
6739 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6741 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6742 CORE_ADDR real_stop_pc
;
6744 infrun_log_debug ("stepped into subroutine");
6746 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6748 /* I presume that step_over_calls is only 0 when we're
6749 supposed to be stepping at the assembly language level
6750 ("stepi"). Just stop. */
6751 /* And this works the same backward as frontward. MVS */
6752 end_stepping_range (ecs
);
6756 /* Reverse stepping through solib trampolines. */
6758 if (execution_direction
== EXEC_REVERSE
6759 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6760 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6761 || (ecs
->stop_func_start
== 0
6762 && in_solib_dynsym_resolve_code (stop_pc
))))
6764 /* Any solib trampoline code can be handled in reverse
6765 by simply continuing to single-step. We have already
6766 executed the solib function (backwards), and a few
6767 steps will take us back through the trampoline to the
6773 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6775 /* We're doing a "next".
6777 Normal (forward) execution: set a breakpoint at the
6778 callee's return address (the address at which the caller
6781 Reverse (backward) execution. set the step-resume
6782 breakpoint at the start of the function that we just
6783 stepped into (backwards), and continue to there. When we
6784 get there, we'll need to single-step back to the caller. */
6786 if (execution_direction
== EXEC_REVERSE
)
6788 /* If we're already at the start of the function, we've either
6789 just stepped backward into a single instruction function,
6790 or stepped back out of a signal handler to the first instruction
6791 of the function. Just keep going, which will single-step back
6793 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6795 /* Normal function call return (static or dynamic). */
6796 symtab_and_line sr_sal
;
6797 sr_sal
.pc
= ecs
->stop_func_start
;
6798 sr_sal
.pspace
= get_frame_program_space (frame
);
6799 insert_step_resume_breakpoint_at_sal (gdbarch
,
6800 sr_sal
, null_frame_id
);
6804 insert_step_resume_breakpoint_at_caller (frame
);
6810 /* If we are in a function call trampoline (a stub between the
6811 calling routine and the real function), locate the real
6812 function. That's what tells us (a) whether we want to step
6813 into it at all, and (b) what prologue we want to run to the
6814 end of, if we do step into it. */
6815 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6816 if (real_stop_pc
== 0)
6817 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6818 if (real_stop_pc
!= 0)
6819 ecs
->stop_func_start
= real_stop_pc
;
6821 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6823 symtab_and_line sr_sal
;
6824 sr_sal
.pc
= ecs
->stop_func_start
;
6825 sr_sal
.pspace
= get_frame_program_space (frame
);
6827 insert_step_resume_breakpoint_at_sal (gdbarch
,
6828 sr_sal
, null_frame_id
);
6833 /* If we have line number information for the function we are
6834 thinking of stepping into and the function isn't on the skip
6837 If there are several symtabs at that PC (e.g. with include
6838 files), just want to know whether *any* of them have line
6839 numbers. find_pc_line handles this. */
6841 struct symtab_and_line tmp_sal
;
6843 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6844 if (tmp_sal
.line
!= 0
6845 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6847 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6849 if (execution_direction
== EXEC_REVERSE
)
6850 handle_step_into_function_backward (gdbarch
, ecs
);
6852 handle_step_into_function (gdbarch
, ecs
);
6857 /* If we have no line number and the step-stop-if-no-debug is
6858 set, we stop the step so that the user has a chance to switch
6859 in assembly mode. */
6860 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6861 && step_stop_if_no_debug
)
6863 end_stepping_range (ecs
);
6867 if (execution_direction
== EXEC_REVERSE
)
6869 /* If we're already at the start of the function, we've either just
6870 stepped backward into a single instruction function without line
6871 number info, or stepped back out of a signal handler to the first
6872 instruction of the function without line number info. Just keep
6873 going, which will single-step back to the caller. */
6874 if (ecs
->stop_func_start
!= stop_pc
)
6876 /* Set a breakpoint at callee's start address.
6877 From there we can step once and be back in the caller. */
6878 symtab_and_line sr_sal
;
6879 sr_sal
.pc
= ecs
->stop_func_start
;
6880 sr_sal
.pspace
= get_frame_program_space (frame
);
6881 insert_step_resume_breakpoint_at_sal (gdbarch
,
6882 sr_sal
, null_frame_id
);
6886 /* Set a breakpoint at callee's return address (the address
6887 at which the caller will resume). */
6888 insert_step_resume_breakpoint_at_caller (frame
);
6894 /* Reverse stepping through solib trampolines. */
6896 if (execution_direction
== EXEC_REVERSE
6897 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6899 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6901 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6902 || (ecs
->stop_func_start
== 0
6903 && in_solib_dynsym_resolve_code (stop_pc
)))
6905 /* Any solib trampoline code can be handled in reverse
6906 by simply continuing to single-step. We have already
6907 executed the solib function (backwards), and a few
6908 steps will take us back through the trampoline to the
6913 else if (in_solib_dynsym_resolve_code (stop_pc
))
6915 /* Stepped backward into the solib dynsym resolver.
6916 Set a breakpoint at its start and continue, then
6917 one more step will take us out. */
6918 symtab_and_line sr_sal
;
6919 sr_sal
.pc
= ecs
->stop_func_start
;
6920 sr_sal
.pspace
= get_frame_program_space (frame
);
6921 insert_step_resume_breakpoint_at_sal (gdbarch
,
6922 sr_sal
, null_frame_id
);
6928 /* This always returns the sal for the inner-most frame when we are in a
6929 stack of inlined frames, even if GDB actually believes that it is in a
6930 more outer frame. This is checked for below by calls to
6931 inline_skipped_frames. */
6932 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6934 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6935 the trampoline processing logic, however, there are some trampolines
6936 that have no names, so we should do trampoline handling first. */
6937 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6938 && ecs
->stop_func_name
== NULL
6939 && stop_pc_sal
.line
== 0)
6941 infrun_log_debug ("stepped into undebuggable function");
6943 /* The inferior just stepped into, or returned to, an
6944 undebuggable function (where there is no debugging information
6945 and no line number corresponding to the address where the
6946 inferior stopped). Since we want to skip this kind of code,
6947 we keep going until the inferior returns from this
6948 function - unless the user has asked us not to (via
6949 set step-mode) or we no longer know how to get back
6950 to the call site. */
6951 if (step_stop_if_no_debug
6952 || !frame_id_p (frame_unwind_caller_id (frame
)))
6954 /* If we have no line number and the step-stop-if-no-debug
6955 is set, we stop the step so that the user has a chance to
6956 switch in assembly mode. */
6957 end_stepping_range (ecs
);
6962 /* Set a breakpoint at callee's return address (the address
6963 at which the caller will resume). */
6964 insert_step_resume_breakpoint_at_caller (frame
);
6970 if (ecs
->event_thread
->control
.step_range_end
== 1)
6972 /* It is stepi or nexti. We always want to stop stepping after
6974 infrun_log_debug ("stepi/nexti");
6975 end_stepping_range (ecs
);
6979 if (stop_pc_sal
.line
== 0)
6981 /* We have no line number information. That means to stop
6982 stepping (does this always happen right after one instruction,
6983 when we do "s" in a function with no line numbers,
6984 or can this happen as a result of a return or longjmp?). */
6985 infrun_log_debug ("line number info");
6986 end_stepping_range (ecs
);
6990 /* Look for "calls" to inlined functions, part one. If the inline
6991 frame machinery detected some skipped call sites, we have entered
6992 a new inline function. */
6994 if (frame_id_eq (get_frame_id (get_current_frame ()),
6995 ecs
->event_thread
->control
.step_frame_id
)
6996 && inline_skipped_frames (ecs
->event_thread
))
6998 infrun_log_debug ("stepped into inlined function");
7000 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7002 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7004 /* For "step", we're going to stop. But if the call site
7005 for this inlined function is on the same source line as
7006 we were previously stepping, go down into the function
7007 first. Otherwise stop at the call site. */
7009 if (call_sal
.line
== ecs
->event_thread
->current_line
7010 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7012 step_into_inline_frame (ecs
->event_thread
);
7013 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7020 end_stepping_range (ecs
);
7025 /* For "next", we should stop at the call site if it is on a
7026 different source line. Otherwise continue through the
7027 inlined function. */
7028 if (call_sal
.line
== ecs
->event_thread
->current_line
7029 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7032 end_stepping_range (ecs
);
7037 /* Look for "calls" to inlined functions, part two. If we are still
7038 in the same real function we were stepping through, but we have
7039 to go further up to find the exact frame ID, we are stepping
7040 through a more inlined call beyond its call site. */
7042 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7043 && !frame_id_eq (get_frame_id (get_current_frame ()),
7044 ecs
->event_thread
->control
.step_frame_id
)
7045 && stepped_in_from (get_current_frame (),
7046 ecs
->event_thread
->control
.step_frame_id
))
7048 infrun_log_debug ("stepping through inlined function");
7050 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7051 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7054 end_stepping_range (ecs
);
7058 bool refresh_step_info
= true;
7059 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7060 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7061 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7063 if (stop_pc_sal
.is_stmt
)
7065 /* We are at the start of a different line. So stop. Note that
7066 we don't stop if we step into the middle of a different line.
7067 That is said to make things like for (;;) statements work
7069 infrun_log_debug ("infrun: stepped to a different line\n");
7070 end_stepping_range (ecs
);
7073 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7074 ecs
->event_thread
->control
.step_frame_id
))
7076 /* We are at the start of a different line, however, this line is
7077 not marked as a statement, and we have not changed frame. We
7078 ignore this line table entry, and continue stepping forward,
7079 looking for a better place to stop. */
7080 refresh_step_info
= false;
7081 infrun_log_debug ("infrun: stepped to a different line, but "
7082 "it's not the start of a statement\n");
7086 /* We aren't done stepping.
7088 Optimize by setting the stepping range to the line.
7089 (We might not be in the original line, but if we entered a
7090 new line in mid-statement, we continue stepping. This makes
7091 things like for(;;) statements work better.)
7093 If we entered a SAL that indicates a non-statement line table entry,
7094 then we update the stepping range, but we don't update the step info,
7095 which includes things like the line number we are stepping away from.
7096 This means we will stop when we find a line table entry that is marked
7097 as is-statement, even if it matches the non-statement one we just
7100 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7101 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7102 ecs
->event_thread
->control
.may_range_step
= 1;
7103 if (refresh_step_info
)
7104 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7106 infrun_log_debug ("keep going");
7110 /* In all-stop mode, if we're currently stepping but have stopped in
7111 some other thread, we may need to switch back to the stepped
7112 thread. Returns true we set the inferior running, false if we left
7113 it stopped (and the event needs further processing). */
7116 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7118 if (!target_is_non_stop_p ())
7120 struct thread_info
*stepping_thread
;
7122 /* If any thread is blocked on some internal breakpoint, and we
7123 simply need to step over that breakpoint to get it going
7124 again, do that first. */
7126 /* However, if we see an event for the stepping thread, then we
7127 know all other threads have been moved past their breakpoints
7128 already. Let the caller check whether the step is finished,
7129 etc., before deciding to move it past a breakpoint. */
7130 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7133 /* Check if the current thread is blocked on an incomplete
7134 step-over, interrupted by a random signal. */
7135 if (ecs
->event_thread
->control
.trap_expected
7136 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7138 infrun_log_debug ("need to finish step-over of [%s]",
7139 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7144 /* Check if the current thread is blocked by a single-step
7145 breakpoint of another thread. */
7146 if (ecs
->hit_singlestep_breakpoint
)
7148 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7149 target_pid_to_str (ecs
->ptid
).c_str ());
7154 /* If this thread needs yet another step-over (e.g., stepping
7155 through a delay slot), do it first before moving on to
7157 if (thread_still_needs_step_over (ecs
->event_thread
))
7160 ("thread [%s] still needs step-over",
7161 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7166 /* If scheduler locking applies even if not stepping, there's no
7167 need to walk over threads. Above we've checked whether the
7168 current thread is stepping. If some other thread not the
7169 event thread is stepping, then it must be that scheduler
7170 locking is not in effect. */
7171 if (schedlock_applies (ecs
->event_thread
))
7174 /* Otherwise, we no longer expect a trap in the current thread.
7175 Clear the trap_expected flag before switching back -- this is
7176 what keep_going does as well, if we call it. */
7177 ecs
->event_thread
->control
.trap_expected
= 0;
7179 /* Likewise, clear the signal if it should not be passed. */
7180 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7181 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7183 /* Do all pending step-overs before actually proceeding with
7185 if (start_step_over ())
7187 prepare_to_wait (ecs
);
7191 /* Look for the stepping/nexting thread. */
7192 stepping_thread
= NULL
;
7194 for (thread_info
*tp
: all_non_exited_threads ())
7196 switch_to_thread_no_regs (tp
);
7198 /* Ignore threads of processes the caller is not
7201 && (tp
->inf
->process_target () != ecs
->target
7202 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7205 /* When stepping over a breakpoint, we lock all threads
7206 except the one that needs to move past the breakpoint.
7207 If a non-event thread has this set, the "incomplete
7208 step-over" check above should have caught it earlier. */
7209 if (tp
->control
.trap_expected
)
7211 internal_error (__FILE__
, __LINE__
,
7212 "[%s] has inconsistent state: "
7213 "trap_expected=%d\n",
7214 target_pid_to_str (tp
->ptid
).c_str (),
7215 tp
->control
.trap_expected
);
7218 /* Did we find the stepping thread? */
7219 if (tp
->control
.step_range_end
)
7221 /* Yep. There should only one though. */
7222 gdb_assert (stepping_thread
== NULL
);
7224 /* The event thread is handled at the top, before we
7226 gdb_assert (tp
!= ecs
->event_thread
);
7228 /* If some thread other than the event thread is
7229 stepping, then scheduler locking can't be in effect,
7230 otherwise we wouldn't have resumed the current event
7231 thread in the first place. */
7232 gdb_assert (!schedlock_applies (tp
));
7234 stepping_thread
= tp
;
7238 if (stepping_thread
!= NULL
)
7240 infrun_log_debug ("switching back to stepped thread");
7242 if (keep_going_stepped_thread (stepping_thread
))
7244 prepare_to_wait (ecs
);
7249 switch_to_thread (ecs
->event_thread
);
7255 /* Set a previously stepped thread back to stepping. Returns true on
7256 success, false if the resume is not possible (e.g., the thread
7260 keep_going_stepped_thread (struct thread_info
*tp
)
7262 struct frame_info
*frame
;
7263 struct execution_control_state ecss
;
7264 struct execution_control_state
*ecs
= &ecss
;
7266 /* If the stepping thread exited, then don't try to switch back and
7267 resume it, which could fail in several different ways depending
7268 on the target. Instead, just keep going.
7270 We can find a stepping dead thread in the thread list in two
7273 - The target supports thread exit events, and when the target
7274 tries to delete the thread from the thread list, inferior_ptid
7275 pointed at the exiting thread. In such case, calling
7276 delete_thread does not really remove the thread from the list;
7277 instead, the thread is left listed, with 'exited' state.
7279 - The target's debug interface does not support thread exit
7280 events, and so we have no idea whatsoever if the previously
7281 stepping thread is still alive. For that reason, we need to
7282 synchronously query the target now. */
7284 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7286 infrun_log_debug ("not resuming previously stepped thread, it has "
7293 infrun_log_debug ("resuming previously stepped thread");
7295 reset_ecs (ecs
, tp
);
7296 switch_to_thread (tp
);
7298 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7299 frame
= get_current_frame ();
7301 /* If the PC of the thread we were trying to single-step has
7302 changed, then that thread has trapped or been signaled, but the
7303 event has not been reported to GDB yet. Re-poll the target
7304 looking for this particular thread's event (i.e. temporarily
7305 enable schedlock) by:
7307 - setting a break at the current PC
7308 - resuming that particular thread, only (by setting trap
7311 This prevents us continuously moving the single-step breakpoint
7312 forward, one instruction at a time, overstepping. */
7314 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7318 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7319 paddress (target_gdbarch (), tp
->prev_pc
),
7320 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7322 /* Clear the info of the previous step-over, as it's no longer
7323 valid (if the thread was trying to step over a breakpoint, it
7324 has already succeeded). It's what keep_going would do too,
7325 if we called it. Do this before trying to insert the sss
7326 breakpoint, otherwise if we were previously trying to step
7327 over this exact address in another thread, the breakpoint is
7329 clear_step_over_info ();
7330 tp
->control
.trap_expected
= 0;
7332 insert_single_step_breakpoint (get_frame_arch (frame
),
7333 get_frame_address_space (frame
),
7334 tp
->suspend
.stop_pc
);
7337 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7338 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7342 infrun_log_debug ("expected thread still hasn't advanced");
7344 keep_going_pass_signal (ecs
);
7349 /* Is thread TP in the middle of (software or hardware)
7350 single-stepping? (Note the result of this function must never be
7351 passed directly as target_resume's STEP parameter.) */
7354 currently_stepping (struct thread_info
*tp
)
7356 return ((tp
->control
.step_range_end
7357 && tp
->control
.step_resume_breakpoint
== NULL
)
7358 || tp
->control
.trap_expected
7359 || tp
->stepped_breakpoint
7360 || bpstat_should_step ());
7363 /* Inferior has stepped into a subroutine call with source code that
7364 we should not step over. Do step to the first line of code in
7368 handle_step_into_function (struct gdbarch
*gdbarch
,
7369 struct execution_control_state
*ecs
)
7371 fill_in_stop_func (gdbarch
, ecs
);
7373 compunit_symtab
*cust
7374 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7375 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7376 ecs
->stop_func_start
7377 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7379 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7380 /* Use the step_resume_break to step until the end of the prologue,
7381 even if that involves jumps (as it seems to on the vax under
7383 /* If the prologue ends in the middle of a source line, continue to
7384 the end of that source line (if it is still within the function).
7385 Otherwise, just go to end of prologue. */
7386 if (stop_func_sal
.end
7387 && stop_func_sal
.pc
!= ecs
->stop_func_start
7388 && stop_func_sal
.end
< ecs
->stop_func_end
)
7389 ecs
->stop_func_start
= stop_func_sal
.end
;
7391 /* Architectures which require breakpoint adjustment might not be able
7392 to place a breakpoint at the computed address. If so, the test
7393 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7394 ecs->stop_func_start to an address at which a breakpoint may be
7395 legitimately placed.
7397 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7398 made, GDB will enter an infinite loop when stepping through
7399 optimized code consisting of VLIW instructions which contain
7400 subinstructions corresponding to different source lines. On
7401 FR-V, it's not permitted to place a breakpoint on any but the
7402 first subinstruction of a VLIW instruction. When a breakpoint is
7403 set, GDB will adjust the breakpoint address to the beginning of
7404 the VLIW instruction. Thus, we need to make the corresponding
7405 adjustment here when computing the stop address. */
7407 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7409 ecs
->stop_func_start
7410 = gdbarch_adjust_breakpoint_address (gdbarch
,
7411 ecs
->stop_func_start
);
7414 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7416 /* We are already there: stop now. */
7417 end_stepping_range (ecs
);
7422 /* Put the step-breakpoint there and go until there. */
7423 symtab_and_line sr_sal
;
7424 sr_sal
.pc
= ecs
->stop_func_start
;
7425 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7426 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7428 /* Do not specify what the fp should be when we stop since on
7429 some machines the prologue is where the new fp value is
7431 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7433 /* And make sure stepping stops right away then. */
7434 ecs
->event_thread
->control
.step_range_end
7435 = ecs
->event_thread
->control
.step_range_start
;
7440 /* Inferior has stepped backward into a subroutine call with source
7441 code that we should not step over. Do step to the beginning of the
7442 last line of code in it. */
7445 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7446 struct execution_control_state
*ecs
)
7448 struct compunit_symtab
*cust
;
7449 struct symtab_and_line stop_func_sal
;
7451 fill_in_stop_func (gdbarch
, ecs
);
7453 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7454 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7455 ecs
->stop_func_start
7456 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7458 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7460 /* OK, we're just going to keep stepping here. */
7461 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7463 /* We're there already. Just stop stepping now. */
7464 end_stepping_range (ecs
);
7468 /* Else just reset the step range and keep going.
7469 No step-resume breakpoint, they don't work for
7470 epilogues, which can have multiple entry paths. */
7471 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7472 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7478 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7479 This is used to both functions and to skip over code. */
7482 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7483 struct symtab_and_line sr_sal
,
7484 struct frame_id sr_id
,
7485 enum bptype sr_type
)
7487 /* There should never be more than one step-resume or longjmp-resume
7488 breakpoint per thread, so we should never be setting a new
7489 step_resume_breakpoint when one is already active. */
7490 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7491 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7493 infrun_log_debug ("inserting step-resume breakpoint at %s",
7494 paddress (gdbarch
, sr_sal
.pc
));
7496 inferior_thread ()->control
.step_resume_breakpoint
7497 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7501 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7502 struct symtab_and_line sr_sal
,
7503 struct frame_id sr_id
)
7505 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7510 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7511 This is used to skip a potential signal handler.
7513 This is called with the interrupted function's frame. The signal
7514 handler, when it returns, will resume the interrupted function at
7518 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7520 gdb_assert (return_frame
!= NULL
);
7522 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7524 symtab_and_line sr_sal
;
7525 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7526 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7527 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7529 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7530 get_stack_frame_id (return_frame
),
7534 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7535 is used to skip a function after stepping into it (for "next" or if
7536 the called function has no debugging information).
7538 The current function has almost always been reached by single
7539 stepping a call or return instruction. NEXT_FRAME belongs to the
7540 current function, and the breakpoint will be set at the caller's
7543 This is a separate function rather than reusing
7544 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7545 get_prev_frame, which may stop prematurely (see the implementation
7546 of frame_unwind_caller_id for an example). */
7549 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7551 /* We shouldn't have gotten here if we don't know where the call site
7553 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7555 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7557 symtab_and_line sr_sal
;
7558 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7559 frame_unwind_caller_pc (next_frame
));
7560 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7561 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7563 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7564 frame_unwind_caller_id (next_frame
));
7567 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7568 new breakpoint at the target of a jmp_buf. The handling of
7569 longjmp-resume uses the same mechanisms used for handling
7570 "step-resume" breakpoints. */
7573 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7575 /* There should never be more than one longjmp-resume breakpoint per
7576 thread, so we should never be setting a new
7577 longjmp_resume_breakpoint when one is already active. */
7578 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7580 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7581 paddress (gdbarch
, pc
));
7583 inferior_thread ()->control
.exception_resume_breakpoint
=
7584 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7587 /* Insert an exception resume breakpoint. TP is the thread throwing
7588 the exception. The block B is the block of the unwinder debug hook
7589 function. FRAME is the frame corresponding to the call to this
7590 function. SYM is the symbol of the function argument holding the
7591 target PC of the exception. */
7594 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7595 const struct block
*b
,
7596 struct frame_info
*frame
,
7601 struct block_symbol vsym
;
7602 struct value
*value
;
7604 struct breakpoint
*bp
;
7606 vsym
= lookup_symbol_search_name (sym
->search_name (),
7608 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7609 /* If the value was optimized out, revert to the old behavior. */
7610 if (! value_optimized_out (value
))
7612 handler
= value_as_address (value
);
7614 infrun_log_debug ("exception resume at %lx",
7615 (unsigned long) handler
);
7617 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7619 bp_exception_resume
).release ();
7621 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7624 bp
->thread
= tp
->global_num
;
7625 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7628 catch (const gdb_exception_error
&e
)
7630 /* We want to ignore errors here. */
7634 /* A helper for check_exception_resume that sets an
7635 exception-breakpoint based on a SystemTap probe. */
7638 insert_exception_resume_from_probe (struct thread_info
*tp
,
7639 const struct bound_probe
*probe
,
7640 struct frame_info
*frame
)
7642 struct value
*arg_value
;
7644 struct breakpoint
*bp
;
7646 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7650 handler
= value_as_address (arg_value
);
7652 infrun_log_debug ("exception resume at %s",
7653 paddress (probe
->objfile
->arch (), handler
));
7655 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7656 handler
, bp_exception_resume
).release ();
7657 bp
->thread
= tp
->global_num
;
7658 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7661 /* This is called when an exception has been intercepted. Check to
7662 see whether the exception's destination is of interest, and if so,
7663 set an exception resume breakpoint there. */
7666 check_exception_resume (struct execution_control_state
*ecs
,
7667 struct frame_info
*frame
)
7669 struct bound_probe probe
;
7670 struct symbol
*func
;
7672 /* First see if this exception unwinding breakpoint was set via a
7673 SystemTap probe point. If so, the probe has two arguments: the
7674 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7675 set a breakpoint there. */
7676 probe
= find_probe_by_pc (get_frame_pc (frame
));
7679 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7683 func
= get_frame_function (frame
);
7689 const struct block
*b
;
7690 struct block_iterator iter
;
7694 /* The exception breakpoint is a thread-specific breakpoint on
7695 the unwinder's debug hook, declared as:
7697 void _Unwind_DebugHook (void *cfa, void *handler);
7699 The CFA argument indicates the frame to which control is
7700 about to be transferred. HANDLER is the destination PC.
7702 We ignore the CFA and set a temporary breakpoint at HANDLER.
7703 This is not extremely efficient but it avoids issues in gdb
7704 with computing the DWARF CFA, and it also works even in weird
7705 cases such as throwing an exception from inside a signal
7708 b
= SYMBOL_BLOCK_VALUE (func
);
7709 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7711 if (!SYMBOL_IS_ARGUMENT (sym
))
7718 insert_exception_resume_breakpoint (ecs
->event_thread
,
7724 catch (const gdb_exception_error
&e
)
7730 stop_waiting (struct execution_control_state
*ecs
)
7732 infrun_log_debug ("stop_waiting");
7734 /* Let callers know we don't want to wait for the inferior anymore. */
7735 ecs
->wait_some_more
= 0;
7737 /* If all-stop, but there exists a non-stop target, stop all
7738 threads now that we're presenting the stop to the user. */
7739 if (!non_stop
&& exists_non_stop_target ())
7740 stop_all_threads ();
7743 /* Like keep_going, but passes the signal to the inferior, even if the
7744 signal is set to nopass. */
7747 keep_going_pass_signal (struct execution_control_state
*ecs
)
7749 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7750 gdb_assert (!ecs
->event_thread
->resumed
);
7752 /* Save the pc before execution, to compare with pc after stop. */
7753 ecs
->event_thread
->prev_pc
7754 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7756 if (ecs
->event_thread
->control
.trap_expected
)
7758 struct thread_info
*tp
= ecs
->event_thread
;
7760 infrun_log_debug ("%s has trap_expected set, "
7761 "resuming to collect trap",
7762 target_pid_to_str (tp
->ptid
).c_str ());
7764 /* We haven't yet gotten our trap, and either: intercepted a
7765 non-signal event (e.g., a fork); or took a signal which we
7766 are supposed to pass through to the inferior. Simply
7768 resume (ecs
->event_thread
->suspend
.stop_signal
);
7770 else if (step_over_info_valid_p ())
7772 /* Another thread is stepping over a breakpoint in-line. If
7773 this thread needs a step-over too, queue the request. In
7774 either case, this resume must be deferred for later. */
7775 struct thread_info
*tp
= ecs
->event_thread
;
7777 if (ecs
->hit_singlestep_breakpoint
7778 || thread_still_needs_step_over (tp
))
7780 infrun_log_debug ("step-over already in progress: "
7781 "step-over for %s deferred",
7782 target_pid_to_str (tp
->ptid
).c_str ());
7783 global_thread_step_over_chain_enqueue (tp
);
7787 infrun_log_debug ("step-over in progress: resume of %s deferred",
7788 target_pid_to_str (tp
->ptid
).c_str ());
7793 struct regcache
*regcache
= get_current_regcache ();
7796 step_over_what step_what
;
7798 /* Either the trap was not expected, but we are continuing
7799 anyway (if we got a signal, the user asked it be passed to
7802 We got our expected trap, but decided we should resume from
7805 We're going to run this baby now!
7807 Note that insert_breakpoints won't try to re-insert
7808 already inserted breakpoints. Therefore, we don't
7809 care if breakpoints were already inserted, or not. */
7811 /* If we need to step over a breakpoint, and we're not using
7812 displaced stepping to do so, insert all breakpoints
7813 (watchpoints, etc.) but the one we're stepping over, step one
7814 instruction, and then re-insert the breakpoint when that step
7817 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7819 remove_bp
= (ecs
->hit_singlestep_breakpoint
7820 || (step_what
& STEP_OVER_BREAKPOINT
));
7821 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7823 /* We can't use displaced stepping if we need to step past a
7824 watchpoint. The instruction copied to the scratch pad would
7825 still trigger the watchpoint. */
7827 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7829 set_step_over_info (regcache
->aspace (),
7830 regcache_read_pc (regcache
), remove_wps
,
7831 ecs
->event_thread
->global_num
);
7833 else if (remove_wps
)
7834 set_step_over_info (NULL
, 0, remove_wps
, -1);
7836 /* If we now need to do an in-line step-over, we need to stop
7837 all other threads. Note this must be done before
7838 insert_breakpoints below, because that removes the breakpoint
7839 we're about to step over, otherwise other threads could miss
7841 if (step_over_info_valid_p () && target_is_non_stop_p ())
7842 stop_all_threads ();
7844 /* Stop stepping if inserting breakpoints fails. */
7847 insert_breakpoints ();
7849 catch (const gdb_exception_error
&e
)
7851 exception_print (gdb_stderr
, e
);
7853 clear_step_over_info ();
7857 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7859 resume (ecs
->event_thread
->suspend
.stop_signal
);
7862 prepare_to_wait (ecs
);
7865 /* Called when we should continue running the inferior, because the
7866 current event doesn't cause a user visible stop. This does the
7867 resuming part; waiting for the next event is done elsewhere. */
7870 keep_going (struct execution_control_state
*ecs
)
7872 if (ecs
->event_thread
->control
.trap_expected
7873 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7874 ecs
->event_thread
->control
.trap_expected
= 0;
7876 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7877 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7878 keep_going_pass_signal (ecs
);
7881 /* This function normally comes after a resume, before
7882 handle_inferior_event exits. It takes care of any last bits of
7883 housekeeping, and sets the all-important wait_some_more flag. */
7886 prepare_to_wait (struct execution_control_state
*ecs
)
7888 infrun_log_debug ("prepare_to_wait");
7890 ecs
->wait_some_more
= 1;
7892 if (!target_is_async_p ())
7893 mark_infrun_async_event_handler ();
7896 /* We are done with the step range of a step/next/si/ni command.
7897 Called once for each n of a "step n" operation. */
7900 end_stepping_range (struct execution_control_state
*ecs
)
7902 ecs
->event_thread
->control
.stop_step
= 1;
7906 /* Several print_*_reason functions to print why the inferior has stopped.
7907 We always print something when the inferior exits, or receives a signal.
7908 The rest of the cases are dealt with later on in normal_stop and
7909 print_it_typical. Ideally there should be a call to one of these
7910 print_*_reason functions functions from handle_inferior_event each time
7911 stop_waiting is called.
7913 Note that we don't call these directly, instead we delegate that to
7914 the interpreters, through observers. Interpreters then call these
7915 with whatever uiout is right. */
7918 print_end_stepping_range_reason (struct ui_out
*uiout
)
7920 /* For CLI-like interpreters, print nothing. */
7922 if (uiout
->is_mi_like_p ())
7924 uiout
->field_string ("reason",
7925 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7930 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7932 annotate_signalled ();
7933 if (uiout
->is_mi_like_p ())
7935 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7936 uiout
->text ("\nProgram terminated with signal ");
7937 annotate_signal_name ();
7938 uiout
->field_string ("signal-name",
7939 gdb_signal_to_name (siggnal
));
7940 annotate_signal_name_end ();
7942 annotate_signal_string ();
7943 uiout
->field_string ("signal-meaning",
7944 gdb_signal_to_string (siggnal
));
7945 annotate_signal_string_end ();
7946 uiout
->text (".\n");
7947 uiout
->text ("The program no longer exists.\n");
7951 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7953 struct inferior
*inf
= current_inferior ();
7954 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7956 annotate_exited (exitstatus
);
7959 if (uiout
->is_mi_like_p ())
7960 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7961 std::string exit_code_str
7962 = string_printf ("0%o", (unsigned int) exitstatus
);
7963 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7964 plongest (inf
->num
), pidstr
.c_str (),
7965 string_field ("exit-code", exit_code_str
.c_str ()));
7969 if (uiout
->is_mi_like_p ())
7971 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7972 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7973 plongest (inf
->num
), pidstr
.c_str ());
7977 /* Some targets/architectures can do extra processing/display of
7978 segmentation faults. E.g., Intel MPX boundary faults.
7979 Call the architecture dependent function to handle the fault. */
7982 handle_segmentation_fault (struct ui_out
*uiout
)
7984 struct regcache
*regcache
= get_current_regcache ();
7985 struct gdbarch
*gdbarch
= regcache
->arch ();
7987 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7988 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7992 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7994 struct thread_info
*thr
= inferior_thread ();
7998 if (uiout
->is_mi_like_p ())
8000 else if (show_thread_that_caused_stop ())
8004 uiout
->text ("\nThread ");
8005 uiout
->field_string ("thread-id", print_thread_id (thr
));
8007 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8010 uiout
->text (" \"");
8011 uiout
->field_string ("name", name
);
8016 uiout
->text ("\nProgram");
8018 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8019 uiout
->text (" stopped");
8022 uiout
->text (" received signal ");
8023 annotate_signal_name ();
8024 if (uiout
->is_mi_like_p ())
8026 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8027 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8028 annotate_signal_name_end ();
8030 annotate_signal_string ();
8031 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8033 if (siggnal
== GDB_SIGNAL_SEGV
)
8034 handle_segmentation_fault (uiout
);
8036 annotate_signal_string_end ();
8038 uiout
->text (".\n");
8042 print_no_history_reason (struct ui_out
*uiout
)
8044 uiout
->text ("\nNo more reverse-execution history.\n");
8047 /* Print current location without a level number, if we have changed
8048 functions or hit a breakpoint. Print source line if we have one.
8049 bpstat_print contains the logic deciding in detail what to print,
8050 based on the event(s) that just occurred. */
8053 print_stop_location (struct target_waitstatus
*ws
)
8056 enum print_what source_flag
;
8057 int do_frame_printing
= 1;
8058 struct thread_info
*tp
= inferior_thread ();
8060 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8064 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8065 should) carry around the function and does (or should) use
8066 that when doing a frame comparison. */
8067 if (tp
->control
.stop_step
8068 && frame_id_eq (tp
->control
.step_frame_id
,
8069 get_frame_id (get_current_frame ()))
8070 && (tp
->control
.step_start_function
8071 == find_pc_function (tp
->suspend
.stop_pc
)))
8073 /* Finished step, just print source line. */
8074 source_flag
= SRC_LINE
;
8078 /* Print location and source line. */
8079 source_flag
= SRC_AND_LOC
;
8082 case PRINT_SRC_AND_LOC
:
8083 /* Print location and source line. */
8084 source_flag
= SRC_AND_LOC
;
8086 case PRINT_SRC_ONLY
:
8087 source_flag
= SRC_LINE
;
8090 /* Something bogus. */
8091 source_flag
= SRC_LINE
;
8092 do_frame_printing
= 0;
8095 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8098 /* The behavior of this routine with respect to the source
8100 SRC_LINE: Print only source line
8101 LOCATION: Print only location
8102 SRC_AND_LOC: Print location and source line. */
8103 if (do_frame_printing
)
8104 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8110 print_stop_event (struct ui_out
*uiout
, bool displays
)
8112 struct target_waitstatus last
;
8113 struct thread_info
*tp
;
8115 get_last_target_status (nullptr, nullptr, &last
);
8118 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8120 print_stop_location (&last
);
8122 /* Display the auto-display expressions. */
8127 tp
= inferior_thread ();
8128 if (tp
->thread_fsm
!= NULL
8129 && tp
->thread_fsm
->finished_p ())
8131 struct return_value_info
*rv
;
8133 rv
= tp
->thread_fsm
->return_value ();
8135 print_return_value (uiout
, rv
);
8142 maybe_remove_breakpoints (void)
8144 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8146 if (remove_breakpoints ())
8148 target_terminal::ours_for_output ();
8149 printf_filtered (_("Cannot remove breakpoints because "
8150 "program is no longer writable.\nFurther "
8151 "execution is probably impossible.\n"));
8156 /* The execution context that just caused a normal stop. */
8163 DISABLE_COPY_AND_ASSIGN (stop_context
);
8165 bool changed () const;
8170 /* The event PTID. */
8174 /* If stopp for a thread event, this is the thread that caused the
8176 struct thread_info
*thread
;
8178 /* The inferior that caused the stop. */
8182 /* Initializes a new stop context. If stopped for a thread event, this
8183 takes a strong reference to the thread. */
8185 stop_context::stop_context ()
8187 stop_id
= get_stop_id ();
8188 ptid
= inferior_ptid
;
8189 inf_num
= current_inferior ()->num
;
8191 if (inferior_ptid
!= null_ptid
)
8193 /* Take a strong reference so that the thread can't be deleted
8195 thread
= inferior_thread ();
8202 /* Release a stop context previously created with save_stop_context.
8203 Releases the strong reference to the thread as well. */
8205 stop_context::~stop_context ()
8211 /* Return true if the current context no longer matches the saved stop
8215 stop_context::changed () const
8217 if (ptid
!= inferior_ptid
)
8219 if (inf_num
!= current_inferior ()->num
)
8221 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8223 if (get_stop_id () != stop_id
)
8233 struct target_waitstatus last
;
8235 get_last_target_status (nullptr, nullptr, &last
);
8239 /* If an exception is thrown from this point on, make sure to
8240 propagate GDB's knowledge of the executing state to the
8241 frontend/user running state. A QUIT is an easy exception to see
8242 here, so do this before any filtered output. */
8244 ptid_t finish_ptid
= null_ptid
;
8247 finish_ptid
= minus_one_ptid
;
8248 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8249 || last
.kind
== TARGET_WAITKIND_EXITED
)
8251 /* On some targets, we may still have live threads in the
8252 inferior when we get a process exit event. E.g., for
8253 "checkpoint", when the current checkpoint/fork exits,
8254 linux-fork.c automatically switches to another fork from
8255 within target_mourn_inferior. */
8256 if (inferior_ptid
!= null_ptid
)
8257 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8259 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8260 finish_ptid
= inferior_ptid
;
8262 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8263 if (finish_ptid
!= null_ptid
)
8265 maybe_finish_thread_state
.emplace
8266 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8269 /* As we're presenting a stop, and potentially removing breakpoints,
8270 update the thread list so we can tell whether there are threads
8271 running on the target. With target remote, for example, we can
8272 only learn about new threads when we explicitly update the thread
8273 list. Do this before notifying the interpreters about signal
8274 stops, end of stepping ranges, etc., so that the "new thread"
8275 output is emitted before e.g., "Program received signal FOO",
8276 instead of after. */
8277 update_thread_list ();
8279 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8280 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8282 /* As with the notification of thread events, we want to delay
8283 notifying the user that we've switched thread context until
8284 the inferior actually stops.
8286 There's no point in saying anything if the inferior has exited.
8287 Note that SIGNALLED here means "exited with a signal", not
8288 "received a signal".
8290 Also skip saying anything in non-stop mode. In that mode, as we
8291 don't want GDB to switch threads behind the user's back, to avoid
8292 races where the user is typing a command to apply to thread x,
8293 but GDB switches to thread y before the user finishes entering
8294 the command, fetch_inferior_event installs a cleanup to restore
8295 the current thread back to the thread the user had selected right
8296 after this event is handled, so we're not really switching, only
8297 informing of a stop. */
8299 && previous_inferior_ptid
!= inferior_ptid
8300 && target_has_execution
8301 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8302 && last
.kind
!= TARGET_WAITKIND_EXITED
8303 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8305 SWITCH_THRU_ALL_UIS ()
8307 target_terminal::ours_for_output ();
8308 printf_filtered (_("[Switching to %s]\n"),
8309 target_pid_to_str (inferior_ptid
).c_str ());
8310 annotate_thread_changed ();
8312 previous_inferior_ptid
= inferior_ptid
;
8315 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8317 SWITCH_THRU_ALL_UIS ()
8318 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8320 target_terminal::ours_for_output ();
8321 printf_filtered (_("No unwaited-for children left.\n"));
8325 /* Note: this depends on the update_thread_list call above. */
8326 maybe_remove_breakpoints ();
8328 /* If an auto-display called a function and that got a signal,
8329 delete that auto-display to avoid an infinite recursion. */
8331 if (stopped_by_random_signal
)
8332 disable_current_display ();
8334 SWITCH_THRU_ALL_UIS ()
8336 async_enable_stdin ();
8339 /* Let the user/frontend see the threads as stopped. */
8340 maybe_finish_thread_state
.reset ();
8342 /* Select innermost stack frame - i.e., current frame is frame 0,
8343 and current location is based on that. Handle the case where the
8344 dummy call is returning after being stopped. E.g. the dummy call
8345 previously hit a breakpoint. (If the dummy call returns
8346 normally, we won't reach here.) Do this before the stop hook is
8347 run, so that it doesn't get to see the temporary dummy frame,
8348 which is not where we'll present the stop. */
8349 if (has_stack_frames ())
8351 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8353 /* Pop the empty frame that contains the stack dummy. This
8354 also restores inferior state prior to the call (struct
8355 infcall_suspend_state). */
8356 struct frame_info
*frame
= get_current_frame ();
8358 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8360 /* frame_pop calls reinit_frame_cache as the last thing it
8361 does which means there's now no selected frame. */
8364 select_frame (get_current_frame ());
8366 /* Set the current source location. */
8367 set_current_sal_from_frame (get_current_frame ());
8370 /* Look up the hook_stop and run it (CLI internally handles problem
8371 of stop_command's pre-hook not existing). */
8372 if (stop_command
!= NULL
)
8374 stop_context saved_context
;
8378 execute_cmd_pre_hook (stop_command
);
8380 catch (const gdb_exception
&ex
)
8382 exception_fprintf (gdb_stderr
, ex
,
8383 "Error while running hook_stop:\n");
8386 /* If the stop hook resumes the target, then there's no point in
8387 trying to notify about the previous stop; its context is
8388 gone. Likewise if the command switches thread or inferior --
8389 the observers would print a stop for the wrong
8391 if (saved_context
.changed ())
8395 /* Notify observers about the stop. This is where the interpreters
8396 print the stop event. */
8397 if (inferior_ptid
!= null_ptid
)
8398 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8401 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8403 annotate_stopped ();
8405 if (target_has_execution
)
8407 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8408 && last
.kind
!= TARGET_WAITKIND_EXITED
8409 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8410 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8411 Delete any breakpoint that is to be deleted at the next stop. */
8412 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8415 /* Try to get rid of automatically added inferiors that are no
8416 longer needed. Keeping those around slows down things linearly.
8417 Note that this never removes the current inferior. */
8424 signal_stop_state (int signo
)
8426 return signal_stop
[signo
];
8430 signal_print_state (int signo
)
8432 return signal_print
[signo
];
8436 signal_pass_state (int signo
)
8438 return signal_program
[signo
];
8442 signal_cache_update (int signo
)
8446 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8447 signal_cache_update (signo
);
8452 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8453 && signal_print
[signo
] == 0
8454 && signal_program
[signo
] == 1
8455 && signal_catch
[signo
] == 0);
8459 signal_stop_update (int signo
, int state
)
8461 int ret
= signal_stop
[signo
];
8463 signal_stop
[signo
] = state
;
8464 signal_cache_update (signo
);
8469 signal_print_update (int signo
, int state
)
8471 int ret
= signal_print
[signo
];
8473 signal_print
[signo
] = state
;
8474 signal_cache_update (signo
);
8479 signal_pass_update (int signo
, int state
)
8481 int ret
= signal_program
[signo
];
8483 signal_program
[signo
] = state
;
8484 signal_cache_update (signo
);
8488 /* Update the global 'signal_catch' from INFO and notify the
8492 signal_catch_update (const unsigned int *info
)
8496 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8497 signal_catch
[i
] = info
[i
] > 0;
8498 signal_cache_update (-1);
8499 target_pass_signals (signal_pass
);
8503 sig_print_header (void)
8505 printf_filtered (_("Signal Stop\tPrint\tPass "
8506 "to program\tDescription\n"));
8510 sig_print_info (enum gdb_signal oursig
)
8512 const char *name
= gdb_signal_to_name (oursig
);
8513 int name_padding
= 13 - strlen (name
);
8515 if (name_padding
<= 0)
8518 printf_filtered ("%s", name
);
8519 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8520 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8521 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8522 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8523 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8526 /* Specify how various signals in the inferior should be handled. */
8529 handle_command (const char *args
, int from_tty
)
8531 int digits
, wordlen
;
8532 int sigfirst
, siglast
;
8533 enum gdb_signal oursig
;
8538 error_no_arg (_("signal to handle"));
8541 /* Allocate and zero an array of flags for which signals to handle. */
8543 const size_t nsigs
= GDB_SIGNAL_LAST
;
8544 unsigned char sigs
[nsigs
] {};
8546 /* Break the command line up into args. */
8548 gdb_argv
built_argv (args
);
8550 /* Walk through the args, looking for signal oursigs, signal names, and
8551 actions. Signal numbers and signal names may be interspersed with
8552 actions, with the actions being performed for all signals cumulatively
8553 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8555 for (char *arg
: built_argv
)
8557 wordlen
= strlen (arg
);
8558 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8562 sigfirst
= siglast
= -1;
8564 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8566 /* Apply action to all signals except those used by the
8567 debugger. Silently skip those. */
8570 siglast
= nsigs
- 1;
8572 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8574 SET_SIGS (nsigs
, sigs
, signal_stop
);
8575 SET_SIGS (nsigs
, sigs
, signal_print
);
8577 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8579 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8581 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8583 SET_SIGS (nsigs
, sigs
, signal_print
);
8585 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8587 SET_SIGS (nsigs
, sigs
, signal_program
);
8589 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8591 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8593 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8595 SET_SIGS (nsigs
, sigs
, signal_program
);
8597 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8599 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8600 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8602 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8604 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8606 else if (digits
> 0)
8608 /* It is numeric. The numeric signal refers to our own
8609 internal signal numbering from target.h, not to host/target
8610 signal number. This is a feature; users really should be
8611 using symbolic names anyway, and the common ones like
8612 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8614 sigfirst
= siglast
= (int)
8615 gdb_signal_from_command (atoi (arg
));
8616 if (arg
[digits
] == '-')
8619 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8621 if (sigfirst
> siglast
)
8623 /* Bet he didn't figure we'd think of this case... */
8624 std::swap (sigfirst
, siglast
);
8629 oursig
= gdb_signal_from_name (arg
);
8630 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8632 sigfirst
= siglast
= (int) oursig
;
8636 /* Not a number and not a recognized flag word => complain. */
8637 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8641 /* If any signal numbers or symbol names were found, set flags for
8642 which signals to apply actions to. */
8644 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8646 switch ((enum gdb_signal
) signum
)
8648 case GDB_SIGNAL_TRAP
:
8649 case GDB_SIGNAL_INT
:
8650 if (!allsigs
&& !sigs
[signum
])
8652 if (query (_("%s is used by the debugger.\n\
8653 Are you sure you want to change it? "),
8654 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8659 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8663 case GDB_SIGNAL_DEFAULT
:
8664 case GDB_SIGNAL_UNKNOWN
:
8665 /* Make sure that "all" doesn't print these. */
8674 for (int signum
= 0; signum
< nsigs
; signum
++)
8677 signal_cache_update (-1);
8678 target_pass_signals (signal_pass
);
8679 target_program_signals (signal_program
);
8683 /* Show the results. */
8684 sig_print_header ();
8685 for (; signum
< nsigs
; signum
++)
8687 sig_print_info ((enum gdb_signal
) signum
);
8694 /* Complete the "handle" command. */
8697 handle_completer (struct cmd_list_element
*ignore
,
8698 completion_tracker
&tracker
,
8699 const char *text
, const char *word
)
8701 static const char * const keywords
[] =
8715 signal_completer (ignore
, tracker
, text
, word
);
8716 complete_on_enum (tracker
, keywords
, word
, word
);
8720 gdb_signal_from_command (int num
)
8722 if (num
>= 1 && num
<= 15)
8723 return (enum gdb_signal
) num
;
8724 error (_("Only signals 1-15 are valid as numeric signals.\n\
8725 Use \"info signals\" for a list of symbolic signals."));
8728 /* Print current contents of the tables set by the handle command.
8729 It is possible we should just be printing signals actually used
8730 by the current target (but for things to work right when switching
8731 targets, all signals should be in the signal tables). */
8734 info_signals_command (const char *signum_exp
, int from_tty
)
8736 enum gdb_signal oursig
;
8738 sig_print_header ();
8742 /* First see if this is a symbol name. */
8743 oursig
= gdb_signal_from_name (signum_exp
);
8744 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8746 /* No, try numeric. */
8748 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8750 sig_print_info (oursig
);
8754 printf_filtered ("\n");
8755 /* These ugly casts brought to you by the native VAX compiler. */
8756 for (oursig
= GDB_SIGNAL_FIRST
;
8757 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8758 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8762 if (oursig
!= GDB_SIGNAL_UNKNOWN
8763 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8764 sig_print_info (oursig
);
8767 printf_filtered (_("\nUse the \"handle\" command "
8768 "to change these tables.\n"));
8771 /* The $_siginfo convenience variable is a bit special. We don't know
8772 for sure the type of the value until we actually have a chance to
8773 fetch the data. The type can change depending on gdbarch, so it is
8774 also dependent on which thread you have selected.
8776 1. making $_siginfo be an internalvar that creates a new value on
8779 2. making the value of $_siginfo be an lval_computed value. */
8781 /* This function implements the lval_computed support for reading a
8785 siginfo_value_read (struct value
*v
)
8787 LONGEST transferred
;
8789 /* If we can access registers, so can we access $_siginfo. Likewise
8791 validate_registers_access ();
8794 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8796 value_contents_all_raw (v
),
8798 TYPE_LENGTH (value_type (v
)));
8800 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8801 error (_("Unable to read siginfo"));
8804 /* This function implements the lval_computed support for writing a
8808 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8810 LONGEST transferred
;
8812 /* If we can access registers, so can we access $_siginfo. Likewise
8814 validate_registers_access ();
8816 transferred
= target_write (current_top_target (),
8817 TARGET_OBJECT_SIGNAL_INFO
,
8819 value_contents_all_raw (fromval
),
8821 TYPE_LENGTH (value_type (fromval
)));
8823 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8824 error (_("Unable to write siginfo"));
8827 static const struct lval_funcs siginfo_value_funcs
=
8833 /* Return a new value with the correct type for the siginfo object of
8834 the current thread using architecture GDBARCH. Return a void value
8835 if there's no object available. */
8837 static struct value
*
8838 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8841 if (target_has_stack
8842 && inferior_ptid
!= null_ptid
8843 && gdbarch_get_siginfo_type_p (gdbarch
))
8845 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8847 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8850 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8854 /* infcall_suspend_state contains state about the program itself like its
8855 registers and any signal it received when it last stopped.
8856 This state must be restored regardless of how the inferior function call
8857 ends (either successfully, or after it hits a breakpoint or signal)
8858 if the program is to properly continue where it left off. */
8860 class infcall_suspend_state
8863 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8864 once the inferior function call has finished. */
8865 infcall_suspend_state (struct gdbarch
*gdbarch
,
8866 const struct thread_info
*tp
,
8867 struct regcache
*regcache
)
8868 : m_thread_suspend (tp
->suspend
),
8869 m_registers (new readonly_detached_regcache (*regcache
))
8871 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8873 if (gdbarch_get_siginfo_type_p (gdbarch
))
8875 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8876 size_t len
= TYPE_LENGTH (type
);
8878 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8880 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8881 siginfo_data
.get (), 0, len
) != len
)
8883 /* Errors ignored. */
8884 siginfo_data
.reset (nullptr);
8890 m_siginfo_gdbarch
= gdbarch
;
8891 m_siginfo_data
= std::move (siginfo_data
);
8895 /* Return a pointer to the stored register state. */
8897 readonly_detached_regcache
*registers () const
8899 return m_registers
.get ();
8902 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8904 void restore (struct gdbarch
*gdbarch
,
8905 struct thread_info
*tp
,
8906 struct regcache
*regcache
) const
8908 tp
->suspend
= m_thread_suspend
;
8910 if (m_siginfo_gdbarch
== gdbarch
)
8912 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8914 /* Errors ignored. */
8915 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8916 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8919 /* The inferior can be gone if the user types "print exit(0)"
8920 (and perhaps other times). */
8921 if (target_has_execution
)
8922 /* NB: The register write goes through to the target. */
8923 regcache
->restore (registers ());
8927 /* How the current thread stopped before the inferior function call was
8929 struct thread_suspend_state m_thread_suspend
;
8931 /* The registers before the inferior function call was executed. */
8932 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8934 /* Format of SIGINFO_DATA or NULL if it is not present. */
8935 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8937 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8938 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8939 content would be invalid. */
8940 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8943 infcall_suspend_state_up
8944 save_infcall_suspend_state ()
8946 struct thread_info
*tp
= inferior_thread ();
8947 struct regcache
*regcache
= get_current_regcache ();
8948 struct gdbarch
*gdbarch
= regcache
->arch ();
8950 infcall_suspend_state_up inf_state
8951 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8953 /* Having saved the current state, adjust the thread state, discarding
8954 any stop signal information. The stop signal is not useful when
8955 starting an inferior function call, and run_inferior_call will not use
8956 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8957 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8962 /* Restore inferior session state to INF_STATE. */
8965 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8967 struct thread_info
*tp
= inferior_thread ();
8968 struct regcache
*regcache
= get_current_regcache ();
8969 struct gdbarch
*gdbarch
= regcache
->arch ();
8971 inf_state
->restore (gdbarch
, tp
, regcache
);
8972 discard_infcall_suspend_state (inf_state
);
8976 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8981 readonly_detached_regcache
*
8982 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8984 return inf_state
->registers ();
8987 /* infcall_control_state contains state regarding gdb's control of the
8988 inferior itself like stepping control. It also contains session state like
8989 the user's currently selected frame. */
8991 struct infcall_control_state
8993 struct thread_control_state thread_control
;
8994 struct inferior_control_state inferior_control
;
8997 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8998 int stopped_by_random_signal
= 0;
9000 /* ID if the selected frame when the inferior function call was made. */
9001 struct frame_id selected_frame_id
{};
9004 /* Save all of the information associated with the inferior<==>gdb
9007 infcall_control_state_up
9008 save_infcall_control_state ()
9010 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9011 struct thread_info
*tp
= inferior_thread ();
9012 struct inferior
*inf
= current_inferior ();
9014 inf_status
->thread_control
= tp
->control
;
9015 inf_status
->inferior_control
= inf
->control
;
9017 tp
->control
.step_resume_breakpoint
= NULL
;
9018 tp
->control
.exception_resume_breakpoint
= NULL
;
9020 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9021 chain. If caller's caller is walking the chain, they'll be happier if we
9022 hand them back the original chain when restore_infcall_control_state is
9024 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9027 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9028 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9030 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9036 restore_selected_frame (const frame_id
&fid
)
9038 frame_info
*frame
= frame_find_by_id (fid
);
9040 /* If inf_status->selected_frame_id is NULL, there was no previously
9044 warning (_("Unable to restore previously selected frame."));
9048 select_frame (frame
);
9051 /* Restore inferior session state to INF_STATUS. */
9054 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9056 struct thread_info
*tp
= inferior_thread ();
9057 struct inferior
*inf
= current_inferior ();
9059 if (tp
->control
.step_resume_breakpoint
)
9060 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9062 if (tp
->control
.exception_resume_breakpoint
)
9063 tp
->control
.exception_resume_breakpoint
->disposition
9064 = disp_del_at_next_stop
;
9066 /* Handle the bpstat_copy of the chain. */
9067 bpstat_clear (&tp
->control
.stop_bpstat
);
9069 tp
->control
= inf_status
->thread_control
;
9070 inf
->control
= inf_status
->inferior_control
;
9073 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9074 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9076 if (target_has_stack
)
9078 /* The point of the try/catch is that if the stack is clobbered,
9079 walking the stack might encounter a garbage pointer and
9080 error() trying to dereference it. */
9083 restore_selected_frame (inf_status
->selected_frame_id
);
9085 catch (const gdb_exception_error
&ex
)
9087 exception_fprintf (gdb_stderr
, ex
,
9088 "Unable to restore previously selected frame:\n");
9089 /* Error in restoring the selected frame. Select the
9091 select_frame (get_current_frame ());
9099 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9101 if (inf_status
->thread_control
.step_resume_breakpoint
)
9102 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9103 = disp_del_at_next_stop
;
9105 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9106 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9107 = disp_del_at_next_stop
;
9109 /* See save_infcall_control_state for info on stop_bpstat. */
9110 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9118 clear_exit_convenience_vars (void)
9120 clear_internalvar (lookup_internalvar ("_exitsignal"));
9121 clear_internalvar (lookup_internalvar ("_exitcode"));
9125 /* User interface for reverse debugging:
9126 Set exec-direction / show exec-direction commands
9127 (returns error unless target implements to_set_exec_direction method). */
9129 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9130 static const char exec_forward
[] = "forward";
9131 static const char exec_reverse
[] = "reverse";
9132 static const char *exec_direction
= exec_forward
;
9133 static const char *const exec_direction_names
[] = {
9140 set_exec_direction_func (const char *args
, int from_tty
,
9141 struct cmd_list_element
*cmd
)
9143 if (target_can_execute_reverse
)
9145 if (!strcmp (exec_direction
, exec_forward
))
9146 execution_direction
= EXEC_FORWARD
;
9147 else if (!strcmp (exec_direction
, exec_reverse
))
9148 execution_direction
= EXEC_REVERSE
;
9152 exec_direction
= exec_forward
;
9153 error (_("Target does not support this operation."));
9158 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9159 struct cmd_list_element
*cmd
, const char *value
)
9161 switch (execution_direction
) {
9163 fprintf_filtered (out
, _("Forward.\n"));
9166 fprintf_filtered (out
, _("Reverse.\n"));
9169 internal_error (__FILE__
, __LINE__
,
9170 _("bogus execution_direction value: %d"),
9171 (int) execution_direction
);
9176 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9177 struct cmd_list_element
*c
, const char *value
)
9179 fprintf_filtered (file
, _("Resuming the execution of threads "
9180 "of all processes is %s.\n"), value
);
9183 /* Implementation of `siginfo' variable. */
9185 static const struct internalvar_funcs siginfo_funcs
=
9192 /* Callback for infrun's target events source. This is marked when a
9193 thread has a pending status to process. */
9196 infrun_async_inferior_event_handler (gdb_client_data data
)
9198 inferior_event_handler (INF_REG_EVENT
, NULL
);
9201 void _initialize_infrun ();
9203 _initialize_infrun ()
9205 struct cmd_list_element
*c
;
9207 /* Register extra event sources in the event loop. */
9208 infrun_async_inferior_event_token
9209 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9211 add_info ("signals", info_signals_command
, _("\
9212 What debugger does when program gets various signals.\n\
9213 Specify a signal as argument to print info on that signal only."));
9214 add_info_alias ("handle", "signals", 0);
9216 c
= add_com ("handle", class_run
, handle_command
, _("\
9217 Specify how to handle signals.\n\
9218 Usage: handle SIGNAL [ACTIONS]\n\
9219 Args are signals and actions to apply to those signals.\n\
9220 If no actions are specified, the current settings for the specified signals\n\
9221 will be displayed instead.\n\
9223 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9224 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9225 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9226 The special arg \"all\" is recognized to mean all signals except those\n\
9227 used by the debugger, typically SIGTRAP and SIGINT.\n\
9229 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9230 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9231 Stop means reenter debugger if this signal happens (implies print).\n\
9232 Print means print a message if this signal happens.\n\
9233 Pass means let program see this signal; otherwise program doesn't know.\n\
9234 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9235 Pass and Stop may be combined.\n\
9237 Multiple signals may be specified. Signal numbers and signal names\n\
9238 may be interspersed with actions, with the actions being performed for\n\
9239 all signals cumulatively specified."));
9240 set_cmd_completer (c
, handle_completer
);
9243 stop_command
= add_cmd ("stop", class_obscure
,
9244 not_just_help_class_command
, _("\
9245 There is no `stop' command, but you can set a hook on `stop'.\n\
9246 This allows you to set a list of commands to be run each time execution\n\
9247 of the program stops."), &cmdlist
);
9249 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9250 Set inferior debugging."), _("\
9251 Show inferior debugging."), _("\
9252 When non-zero, inferior specific debugging is enabled."),
9255 &setdebuglist
, &showdebuglist
);
9257 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9258 &debug_displaced
, _("\
9259 Set displaced stepping debugging."), _("\
9260 Show displaced stepping debugging."), _("\
9261 When non-zero, displaced stepping specific debugging is enabled."),
9263 show_debug_displaced
,
9264 &setdebuglist
, &showdebuglist
);
9266 add_setshow_boolean_cmd ("non-stop", no_class
,
9268 Set whether gdb controls the inferior in non-stop mode."), _("\
9269 Show whether gdb controls the inferior in non-stop mode."), _("\
9270 When debugging a multi-threaded program and this setting is\n\
9271 off (the default, also called all-stop mode), when one thread stops\n\
9272 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9273 all other threads in the program while you interact with the thread of\n\
9274 interest. When you continue or step a thread, you can allow the other\n\
9275 threads to run, or have them remain stopped, but while you inspect any\n\
9276 thread's state, all threads stop.\n\
9278 In non-stop mode, when one thread stops, other threads can continue\n\
9279 to run freely. You'll be able to step each thread independently,\n\
9280 leave it stopped or free to run as needed."),
9286 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9289 signal_print
[i
] = 1;
9290 signal_program
[i
] = 1;
9291 signal_catch
[i
] = 0;
9294 /* Signals caused by debugger's own actions should not be given to
9295 the program afterwards.
9297 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9298 explicitly specifies that it should be delivered to the target
9299 program. Typically, that would occur when a user is debugging a
9300 target monitor on a simulator: the target monitor sets a
9301 breakpoint; the simulator encounters this breakpoint and halts
9302 the simulation handing control to GDB; GDB, noting that the stop
9303 address doesn't map to any known breakpoint, returns control back
9304 to the simulator; the simulator then delivers the hardware
9305 equivalent of a GDB_SIGNAL_TRAP to the program being
9307 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9308 signal_program
[GDB_SIGNAL_INT
] = 0;
9310 /* Signals that are not errors should not normally enter the debugger. */
9311 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9312 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9313 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9314 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9315 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9316 signal_print
[GDB_SIGNAL_PROF
] = 0;
9317 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9318 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9319 signal_stop
[GDB_SIGNAL_IO
] = 0;
9320 signal_print
[GDB_SIGNAL_IO
] = 0;
9321 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9322 signal_print
[GDB_SIGNAL_POLL
] = 0;
9323 signal_stop
[GDB_SIGNAL_URG
] = 0;
9324 signal_print
[GDB_SIGNAL_URG
] = 0;
9325 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9326 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9327 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9328 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9330 /* These signals are used internally by user-level thread
9331 implementations. (See signal(5) on Solaris.) Like the above
9332 signals, a healthy program receives and handles them as part of
9333 its normal operation. */
9334 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9335 signal_print
[GDB_SIGNAL_LWP
] = 0;
9336 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9337 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9338 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9339 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9340 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9341 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9343 /* Update cached state. */
9344 signal_cache_update (-1);
9346 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9347 &stop_on_solib_events
, _("\
9348 Set stopping for shared library events."), _("\
9349 Show stopping for shared library events."), _("\
9350 If nonzero, gdb will give control to the user when the dynamic linker\n\
9351 notifies gdb of shared library events. The most common event of interest\n\
9352 to the user would be loading/unloading of a new library."),
9353 set_stop_on_solib_events
,
9354 show_stop_on_solib_events
,
9355 &setlist
, &showlist
);
9357 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9358 follow_fork_mode_kind_names
,
9359 &follow_fork_mode_string
, _("\
9360 Set debugger response to a program call of fork or vfork."), _("\
9361 Show debugger response to a program call of fork or vfork."), _("\
9362 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9363 parent - the original process is debugged after a fork\n\
9364 child - the new process is debugged after a fork\n\
9365 The unfollowed process will continue to run.\n\
9366 By default, the debugger will follow the parent process."),
9368 show_follow_fork_mode_string
,
9369 &setlist
, &showlist
);
9371 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9372 follow_exec_mode_names
,
9373 &follow_exec_mode_string
, _("\
9374 Set debugger response to a program call of exec."), _("\
9375 Show debugger response to a program call of exec."), _("\
9376 An exec call replaces the program image of a process.\n\
9378 follow-exec-mode can be:\n\
9380 new - the debugger creates a new inferior and rebinds the process\n\
9381 to this new inferior. The program the process was running before\n\
9382 the exec call can be restarted afterwards by restarting the original\n\
9385 same - the debugger keeps the process bound to the same inferior.\n\
9386 The new executable image replaces the previous executable loaded in\n\
9387 the inferior. Restarting the inferior after the exec call restarts\n\
9388 the executable the process was running after the exec call.\n\
9390 By default, the debugger will use the same inferior."),
9392 show_follow_exec_mode_string
,
9393 &setlist
, &showlist
);
9395 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9396 scheduler_enums
, &scheduler_mode
, _("\
9397 Set mode for locking scheduler during execution."), _("\
9398 Show mode for locking scheduler during execution."), _("\
9399 off == no locking (threads may preempt at any time)\n\
9400 on == full locking (no thread except the current thread may run)\n\
9401 This applies to both normal execution and replay mode.\n\
9402 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9403 In this mode, other threads may run during other commands.\n\
9404 This applies to both normal execution and replay mode.\n\
9405 replay == scheduler locked in replay mode and unlocked during normal execution."),
9406 set_schedlock_func
, /* traps on target vector */
9407 show_scheduler_mode
,
9408 &setlist
, &showlist
);
9410 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9411 Set mode for resuming threads of all processes."), _("\
9412 Show mode for resuming threads of all processes."), _("\
9413 When on, execution commands (such as 'continue' or 'next') resume all\n\
9414 threads of all processes. When off (which is the default), execution\n\
9415 commands only resume the threads of the current process. The set of\n\
9416 threads that are resumed is further refined by the scheduler-locking\n\
9417 mode (see help set scheduler-locking)."),
9419 show_schedule_multiple
,
9420 &setlist
, &showlist
);
9422 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9423 Set mode of the step operation."), _("\
9424 Show mode of the step operation."), _("\
9425 When set, doing a step over a function without debug line information\n\
9426 will stop at the first instruction of that function. Otherwise, the\n\
9427 function is skipped and the step command stops at a different source line."),
9429 show_step_stop_if_no_debug
,
9430 &setlist
, &showlist
);
9432 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9433 &can_use_displaced_stepping
, _("\
9434 Set debugger's willingness to use displaced stepping."), _("\
9435 Show debugger's willingness to use displaced stepping."), _("\
9436 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9437 supported by the target architecture. If off, gdb will not use displaced\n\
9438 stepping to step over breakpoints, even if such is supported by the target\n\
9439 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9440 if the target architecture supports it and non-stop mode is active, but will not\n\
9441 use it in all-stop mode (see help set non-stop)."),
9443 show_can_use_displaced_stepping
,
9444 &setlist
, &showlist
);
9446 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9447 &exec_direction
, _("Set direction of execution.\n\
9448 Options are 'forward' or 'reverse'."),
9449 _("Show direction of execution (forward/reverse)."),
9450 _("Tells gdb whether to execute forward or backward."),
9451 set_exec_direction_func
, show_exec_direction_func
,
9452 &setlist
, &showlist
);
9454 /* Set/show detach-on-fork: user-settable mode. */
9456 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9457 Set whether gdb will detach the child of a fork."), _("\
9458 Show whether gdb will detach the child of a fork."), _("\
9459 Tells gdb whether to detach the child of a fork."),
9460 NULL
, NULL
, &setlist
, &showlist
);
9462 /* Set/show disable address space randomization mode. */
9464 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9465 &disable_randomization
, _("\
9466 Set disabling of debuggee's virtual address space randomization."), _("\
9467 Show disabling of debuggee's virtual address space randomization."), _("\
9468 When this mode is on (which is the default), randomization of the virtual\n\
9469 address space is disabled. Standalone programs run with the randomization\n\
9470 enabled by default on some platforms."),
9471 &set_disable_randomization
,
9472 &show_disable_randomization
,
9473 &setlist
, &showlist
);
9475 /* ptid initializations */
9476 inferior_ptid
= null_ptid
;
9477 target_last_wait_ptid
= minus_one_ptid
;
9479 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9480 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9481 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9482 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9484 /* Explicitly create without lookup, since that tries to create a
9485 value with a void typed value, and when we get here, gdbarch
9486 isn't initialized yet. At this point, we're quite sure there
9487 isn't another convenience variable of the same name. */
9488 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9490 add_setshow_boolean_cmd ("observer", no_class
,
9491 &observer_mode_1
, _("\
9492 Set whether gdb controls the inferior in observer mode."), _("\
9493 Show whether gdb controls the inferior in observer mode."), _("\
9494 In observer mode, GDB can get data from the inferior, but not\n\
9495 affect its execution. Registers and memory may not be changed,\n\
9496 breakpoints may not be set, and the program cannot be interrupted\n\